Nationals 3, Marlins 2(10)
Lidge gave up a two run-homer to Logan Morrison in the ninth inning that tied the game and nearly wasted another excellent start by Stephen Strasburg. Desmond's fly an inning later made sure Washington's winning ways would continue.
The Nationals improved to 12-4, continuing their best start since moving to Washington from Montreal in 2005. The team is 6-2 in one-run games.
Desmond, who also hit a solo home run in the sixth inning to break a scoreless tie, feels a big change in the clubhouse from last season's 80-81 team.
''What a difference a year makes,'' he said. ''Last year at this time it was a huge struggle. I think I had about eight errors, was hitting .200 and we weren't winning. This year is a new year, a fresh start.''
The Nationals led 2-0 in the ninth inning when Lidge entered to close the game. He gave up a leadoff walk to Hanley Ramirez and then Morrison crushed a home run to tie the game. Lidge walked two other batters before getting out of the inning.
''Obviously, I'm not throwing well out there. My location's bad,'' Lidge said. ''It's frustrating. I don't want to make these guys play extra innings, and I don't want to blow the game for Stras, who threw great.''
Edward Mujica (0-1) came on in the ninth inning for the Marlins and gave up the winning run in the 10th. After Ramos singled to center, pinch-hitter Adam LaRoche grounded to first, and Gaby Sanchez decided to throw to second instead of stepping on first for the out. His throw was high, putting Ramos on third with no outs.
''They made a little boo-boo and it cost them,'' Nationals manager Davey Johnson said.
Shortstop Jose Reyes blamed himself for not coming up with Sanchez's throw.
''If I catch the ball, we make a double play,'' he said.
Desmond's fly ball to centerfielder Emilio Bonifacio was enough to score Ramos, ending the game.
''I had a pretty good idea it was going to be deep enough,'' Desmond said. ''Bonifacio is a pretty good outfielder and he's got a strong arm - once I saw the throw go a little bit wide I started celebrating.''
Tom Gorzelanny (1-0) pitched the top of the 10th inning for the win.
Morrison's homer kept Strasburg from his third win of the season. Strasburg allowed four hits, walked one and struck out six over six scoreless innings in his fourth start of the season.
Strasburg extended a scoreless streak by Washington's starting pitchers to 16 innings and lowered his ERA to 1.08 in his second outing of the year without allowing a run.
Anibal Sanchez threw seven innings and for much of the game looked even stronger than Strasburg, holding the Nationals to two hits over the first five innings before giving up two late home runs. The Marlins' righthander allowed five hits and struck out eight without walking a batter.
Jayson Werth homered in the seventh to give the Nationals a 2-0 lead. It was Werth's first homer of the year and broke a 0 for 11 slump.
Reyes doubled in the fourth with no outs but was left stranded on third. He doubled again in the sixth and the Marlins had runners on first and second with two outs before Strasburg got out of the jam.
Strasburg watched the end of the game from the dugout, and celebrated with the team after Ramos scored the game winner.
''It's awesome. The season's still young, but we've pulled the close ones out,'' Strasburg said. ''Definitely, there's no sense of panic when we get into that situation.''
NOTES: Nationals 3B Ryan Zimmerman was replaced by Mark DeRosa in the lineup just before the game because of mild right shoulder inflammation. The team said there was no structural damage. Zimmerman said he expects to return Tuesday - he will sit out Sunday's game and the Nationals have an off day Monday. ... Washington's Chad Tracy got his first start of the season in the cleanup spot as regular 1B Adam LaRoche was given a rest. ... It was Strasburg's 21st career start and fifth against the Marlins. He hasn't faced any other team more than twice. ... In 17 previous games against Washingotn, Sanchez was 7-0 with a 2.06 ERA. ...Washington LHP Gio Gonzalez (1-0, 2.04 ERA) will face Marlins RHP Josh Johnson (0-2, 5.94 ERA) in the final of the three-game series Sunday.