Novak Djokovic rips off his shirt and celebrates after defeating Stanislas Wawrinka in an epic fourth-round match at the Australian Open on Sunday, Jan. 20. The pair battled for more than five hours.

Novak Djokovic gave Stanislas Wawrinka an embrace after beating him in the longest match yet at this Australian Open. Djokovic won the five-set match with a 12-10 tiebreaker in the final set.

A packed crowd stayed until past 2 a.m. in Melbourne to see Novak Djokovic pull off another marathon victory at the Australian Open.

Stanislas Wawrinka was an unlikely candidate to push Novak Djokovic so hard, but the 15th seed gave it his all in losing a five-hour marathon.

Novak Djokovic seemed to get stronger as his fourth-round match against Stanislas Wawrinka went on. Wawrinka dominated the early action, but the top-seeded Djokovic had enoug in reserve to win an epic fifth set.

Stanislas Wawrinka had the top-seeded Novak Djokovic on the ropes early but let him back in the match in the second set. After that, the two slugged it out until just after 2 a.m. in Melbourne.

Novak Djokovic was all over the court trying to keep up with Stanislas Wawrinka's tough service game, battling for five hours to get the hard-earned victory.

Russia's Ekaterina Makarova hits a forehand return to Germany's Angelique Kerber during their fourth-round match at the Australian Open Sunday in Melbourne. The No. 19-seed Makarova pulled off the upset over fifth-seeded Kerber.

Germany's Angelique Kerber hits a forehand return to Russia's Ekaterina Makarova during their fourth-round match Sunday. The No. 5 seed Kerber fell in an upset.

Russia's Ekaterina Makarova (right) walks past her opponent, Germany's Angelique Kerber, during their fourth-round match Sunday.

Germany's Angelique Kerber (left) congratulates Russia's Ekaterina Makarova following Makarova's upset 7-5, 6-4 win.

Spain's David Ferrer ties his bandana during his fourth-round match against Japan's Kei Nishikori Sunday. The No. 4 seed Ferrer won convincingly in straight sets.

Spain's David Ferrer (left) is congratulated by Japan's Kei Nishikori after their fourth-round match, with the 30-year-old Ferrer advancing with a 6-2, 6-1, 6-4 win.

In a week of news dominated by unsportsmanlike conduct (ahem, Lance Armstrong), it's refreshng to see two players — France's Jo-Wilfried Tsonga, right, and Slovenia's Blaz Kavcic — commend each other's performance post-match.

Switzerland's Roger Federer serves to Australia's Bernard Tomic during their third-round match. Federer beat the 20-year-old in straight sets to reach the fourth round.

Frenchmen Gael Monfils and Gilles Simon meet at the net after a hard-fought five-set match. Simon came out the winner and will play Andy Murray next.

Britain's Andy Murray celebrates after defeating Lithuania's Ricardas Berankis in their third-round match at the Australian Open. Murray will play France's Gilles Simon in the fourth round.

Sloane Stephens of the US makes a backhand return to Britain's Laura Robson during their third-round match at the Australian Open. Stephens won the battle of the two up-and-comers and is just one match away from a meeting with her mentor, Serena Williams, in the quarterfinal round.

Roger Federer of Switzerland shakes hands with 20-year-old Bernard Tomic of Australia after their third-round match. Federer won in straight sets.

World No. 1 Victoria Azarenka of Belarus hits a return to Jamie Hampton of the US during their third-round match. Hampton and Azarenka split the first two sets forcing a decisive third set.

Belgium's Yanina Wickmayer rests during her third-round match against Russia's Maria Kirilenko at the Australian Open.

Victoria Azarenka of Belarus hits a return to Jamie Hampton of the US during their third-round match.

Jamie Hampton of the United States plays a backhand to No. 1 Victoria Azarenka of Belarus in their third-round match. Hampered by a nagging back injury Hampton was able to take Azarenka to a third set.

Marcos Baghdatis of Cyprus gets horizontal during his third-round match against No. 4 David Ferrer. Ferrer won to reach the fourth round where he'll play the No. 16 seed Kel Nishikori.

... and eating it, too. Germany's Angelique Kerber is presented with a birthday cake following her 6-2, 7-5 third-round win over Madison Keys of the US on Friday. Kerber turned 25; Keys is 17.

Kerber really dug in for her 25th birthday after feasting on teen Madison Keys on the court.

Serbia's Novak Djokovic was stretched to his limits on some points by Radek Stepanek of the Czech Republic during their third-round match on Friday, but overall the top-ranked player in the world had little trouble.

Djokovic waves as he leaves Rod Laver Arena after sweeping Stepanek on Friday, 6-4, 6-3, 7-5. The win propelled Djokovic to the fourth round and stretched his winning streak at the Australian Open to 17 matches.

South Africa's Kevin Anderson changes his shirt during a break in his third-round match against Spain's Fernando Verdasco on Friday. In doing so, he exposes his bandage on his injured shoulder. After the break, Anderson finished off a five-set win over the 22nd-seeded player, 4-6, 6-3, 4-6, 7-6 (4), 6-2.

Spain's Nicolas Almagro needed to do some work against 24th-seeded Jerzy Janowicz of Poland, but was able to let out a big roar after the No. 10 seed finished off a 7-6 (3), 7-6 (4), 6-1 win on Friday.

Agnieszka Radwanska entered the third round 11-0. Let's make it a perfect dozen after a sweep of Heather Watson of Great Britain. That deserves a wave.

Britain's Heather Watson searches for answers in her chair against Poland's Agnieszka Radwanska on Friday. Alas, there were none as Watson was bounced in the third round 6-3, 6-1.

Ana Ivanovic reacts during Friday's third-round win over compatriot Jelena Jankovic. Ivanovic won the matchup of former world No. 1s 7-5, 6-3.

China's Li Na has one career Grand Slam title — the 2011 French Open. If she keeps playing the way she did on Friday (a 6-4, 6-1 win over Romania's Sorana Cirstea), she may leave Melbourne with her second.

Laura Robson of Great Britain serves in her second-round match against Petra Kvitova of the Czech Republic. Robson won a tough three-set match well after midnight in Melbourne and will face Sloane Stephens in the third round.

2011 Wimbledon champion Petra Kvitova of the Czech Republic plays a forehand in her second-round match against Laura Robson. Kvitova could not overpower her younger opponent and lost her bid at a second Slam title.

Switzerland's Roger Federer doesn't miss a beat as he hits a forehand return to Russia's Nikolay Davydenko. Federer won in straight sets to reach the third round.

Slovenia's Blaz Kavcic celebrates after defeating Australia's James Duckworth in their second-round match at the Australian Open.

Belgium's Yanina Wickmayer attempts to cool off during a second-round match against Slovakia's Jana Cepelova on Thursday. Wickmayer, seeded 20th, advanced with a 7-6, 7-5 victory.

Russia's Maria Kirilenko reacts after a shot in her second-round victory over China's Shuai Peng on Thursday. The 14th-seeded Kirilenko won 7-5, 6-2.

Japan's Ayumi Morita reacts after winning a point against Germany's Annika Beck during their second-round match Thursday. Morita advanced with a 6-2, 6-0 victory.

Top-seeded Victoria Azarenka of Belarus writes on the camera lens after winning her second-round match over Greece's Eleni Daniilidou on Thursday. Azarenka dropped just one game, winning 6-1, 6-0.

It's never easy having to play a No. 1 seed. Eleni Daniilidou reacts after a point during her second-round, 6-1, 6-0 loss to top-seeded Victoria Azarenka on Thursday.

Third-seeded Serena Williams hits a backhand return to Spain's Garbine Muguruza during their second-round match Thursday. Williams cruised to a 6-2, 6-0 victory.

Serbia's Novak Djokovic celebrates after defeating Ryan Harrison of the US rather handily in their second-round match at the Australian Open.

Britain's Heather Watson celebrates after winning her second-round match over Ksenia Pervak of Kazakstan. Watson will next meet No. 4 Agnieszka Radwanska who is undefeated in 2013.

Venus Williams of the US hits a return to France's Alize Cornet in their second-round match. Venus showed off her lastest design on the court as she worked her way into the third round.

Slovakia's Lukas Lacko reacts during his loss to Serbia's Janko Tipsarevic in their second-round match. The 8th-seeded Tipsarevic needed five sets to advance.

Russia's Maria Sharapova followed-up her first-round double bagel with . . . another one. In Wednesday's Round 2, the star took care of Misaki Doi of Japan, 6-0, 6-0. The match lasted all of 47 minutes and Sharapova dropped all of 15 points.

Agnieszka Radwanska of Poland celebrates winning her second-round match against Irina-Camelia Begu of Romania on Wednesday. The win took Radwanska to 11-0 on the season.

Perfect is about the last adjective one would use to describe ninth-seeded Sam Stosur's second-round match on native soil. Despite leading 5-2 in the third set and sitting only two points from advancing, and serving for the match multiple times, Stosur lost the final games of the match and ended with a double fault, getting bounced by Jie Zheng of China.

Jie Zheng of China celebrates during her second-round defeat of No. 9 Samantha Stosur.

American Brian Baker grimaces after injuring his knee during his second-round match against countryman Sam Querrey. Baker has undergone numerous surgeries in his career, and has struggled for years to get back on — and stay on — the court.

Brian Baker buries his head in his hands after suffering a knee injury that would not only end his Australian Open despite leading fellow American Sam Querrey in the second round, but will also require surgery and likely keep him sidelined for four months.

Americans Sam Querrey (far left) and Brian Baker talk after Baker retires from Wednesday's second-round match with a knee injury. Baker would ultimately be taken off the court in a wheelchair.

Germany's Tobias Kamke receives treatment from a trainer during his second-round match against Switzerland's Stanislas Warwinka on Wednesday. It was no use, however, as Kamke retired after dropping the first two sets.

Actually, this is a happy face. Poland's Jerzy Janowicz celebrates after his second-round win over India's Somdev Devvarman, a hard-fought, five-set win after dropping the first two sets.

Germany's Angelique Kerber plays a return during her women's singles match against Lucie Hradecka of Czech Republic on Day 3 at the Australian Open. The No. 5 seed Kerber reached the third round in straight sets.
 

Japan's Kei Nishikori hits a backhand return to Argentina's Carlos Berlocq during their second-round match. Nishikori won in straight sets to reach the third round.

Argentina's Carlos Berlocq reaches for a return to Japan's Kei Nishikori during their second-round match. Berlocq lost to the No. 16-seeded Nishikori.
 

Spain's No. 10 seed Nicolas Almagro serves to compatriot Daniel Gimeno-Traver during their second-round match at the Australian Open. Almagro won for a spot in the third round.
 

Bethanie Mattek-Sands (left) of the United States talks tactics with Sania Mirza of India in their first-round doubles match against Silvia Soler-Espinosa of Spain and Carla Suarez Navarro of Spain. Their strategy session didn't work as the duo lost in straight sets.
 

Up 4-0 in the first set of her first-round match on Tuesday, American Serena Williams, the favorite to win in Melbourne, was cruising. But chasing down a cross-court shot, Williams crumpled to the court after rolling her ankle. As opponent Edina Gallovits-Hall of Romania awaited, the tennis world held its breath.

Quickly, medical assistance rushed to the side of 15-time Grand Slam singles champion Serena Williams as her match — and her Australian Open — quickly looked in jeopardy.

Serena Williams is able to stand up with little assistance and make her way to her chair for further assessment on her ankle.

Serena Williams entered the match with her ankle heavily taped, which many speculate helped her ankle better absorb the injury. Ultimately, she was able to continue after getting the ankle re-taped.

Serena Williams certainly recovered from her injury scare, winning the final eight sets after rolling her ankle and putting up a double bagel over Romania's Edina Gallovits-Hall, 6-0, 6-0. Gallovits-Hall won only six points the entire second set. Williams, meanwhile, said after the match, 'I've played this tournament with so many injuries and was able to come off pretty on top. So for me it's just another page and a great story to tell the grandkids one day.' In her post-match news conference, Williams said there was pain and swelling, but that it would be at least several hours before a determination would be made with respect to X-rays being taken.

Beyond the drama of Serena Williams' injury were the 2013 Australian Open debuts of some of tennis' biggest names Tuesdays. And regardless of the continent, they don't get much bigger than Rogers Federer.

Roger Federer waves to the crowd after his convincing 6-2, 6-4, 6-1 win over 23-year-old Frenchman Benoit Paire on Tuesday.

Victoria Azarenka is from Belarus but is the defending champion in Melbourne. And the fans down under certainly love their champion, as they gather to get her autograph following her opening-round 6-1, 6-4 sweep of Monica Niculescu of Romania on Tuesday.

Victoria Azarenka gives her signature tongue wag after defeating Romania's Monica Niculescu on Tuesday.

Jo-Wilfried Tsonga of France adjusts his shirt during his first-round match Tuesday against countryman Michael Llodra.

France's Jo-Wilfried Tsonga used his serve and return games to sweep fellow Frenchman Michael Llodra on Tuesday, 6-4, 7-5, 6-2. The seventh-seeded Tsonga experienced his greatest Grand Slam success at Melbourne advancing to the 2008 Australian Open final before losing to Novak Djokovic.

Britain's Andy Murray takes a drink as he is shielded from the sun during a break in his first-round match against Robin Haase of the Netherlands on Tuesday. Murray, who finally broke through late last season with the US Open championship, swept Haase, 6-3, 6-1, 6-3.

Germany's Sabine Lisicki was focused on this backhand return, and focused in pretty much every point early on against Denmark's Caroline Wozniacki on Tuesday. Lisicki jumped easily won the first set against the former world No. 1, 6-2. But . . .

. . . Caroline Wozniacki got her game together on Tuesday and won the final two sets (including the final six games after trailing 0-3 in the third set) to take down a determined Sabine Lisicki, 2-6, 6-3, 6-3.

John-Patrick Smith of Australia has quite a shirt — and face paint — but not quite a match on Tuesday. He was swept by Joao Sousa of Portugal, 6-4, 6-1, 6-4.

Japan's Kimiko Date-Krumm, all of 42 years of age, is pumped after upsetting No. 12 Nadia Petrova of Russia on Tuesday, 6-2, 6-0.

Germany's No. 5 seed Angelique Kerber celebrates after winning her first-round match against Ukraine's Elina Svitolina at the Australian Open. Kerber will play Czech Republic's Lucie Hradecka in the second round.

After suffering a huge loss in last weekend's Sydney final to the red-hot Agnieszka Radwanska, No. 15 seed Dominika Cibulkova recovers to defeat Aussie teen Ashleigh Barty in three sets.

Serbia's Janko Tipsarevic celebrates after defeating Australia's Lleyton Hewitt in their first-round match at the Australian Open. Tipsarevic had little trouble with the former No. 1 dispatching the crowd-favorite Hewitt in straight sets.

Britain's Heather Watson reacts during her first-round match against Romania's Alexandra Cadantu at the Australian Open. Whatever Watson was thinking, she was able to defeat Cadantu to reach the second round where she'll play Ksenia Pervak.

Poland's Agnieszka Radwanska on Monday does what she has done nine other times this year — celebrates after a win. In fact, her first-round win over Australia's Bojana Bobusic improved her record to a perfect 10-0 in 2013.

Russia's Maria Sharapova serves to compatriot Olga Puchkova during their first-round match at the Australian Open. Sharapova didn't give up one game serving her third career double bagel at a Slam.

Venus Williams must be taking notes from younger sister Serena. She sails through her first-round match against Galina Voskoboeva of Kazakhstan on Jan. 14 with a 6-1, 6-0 win.

Serena Williams and her coach/boyfriend Patrick Mouratoglou watch Venus Williams' first round match. Their presence did the trick as Venus eased through to the second round.

Serbia's Novak Djokovic begins his quest for a third straight Aussie Open title with an easy sweep of France's Paul-Henri Mathieu on Monday. It was Djokovic's first match in the event since last year's epic 5-hour, 53-minute win over Rafael Nadal in the final.

Sixteenth-seeded Kei Nishikori of Japan cools off on Monday with a bag of ice on his head during a break in his first-round match against Romania's Victor Hanescu. Despite the overheating, however, Nishikori won in four sets.

American qualifier Steve Johnson (pictured) took No. 10 Nicolas Almagro of Spain to the limit in Monday's first round, but fell in five sets, 5-7, 7-6 (4), 2-6, 7-6 (6), 2-6.

Told you s Nicolas Almagro was stretched to the limit by Steve Johnson.

Tomas Berdych of the Czech Republic swept American Michael Russell in Monday's first round. Berdych was far from his best, missing on half his first serves. But the little-known Russell, who was actually the third-oldest player in the field at 34, made 42 unforced errors.

If this looks like a warm-up shot, that's because it likely felt like one to Stanislas Wawrinka of Switzerland. The No. 15 seed had no trouble with German qualifier Cedrik-Marcel Stebe, winning in straight sets.

China's Li Na sported purple, played on blue, and struck hold against Kazakstan's Sesil Karatantcheva in the first round Monday, dropping only four games in her sweep.