Hamilton’s time of 1 minute, 34.157 seconds around the Suzuka circuit was just 0.330 seconds faster than Rosberg. Vettel was six tenths of a second off Hamilton’s time.
Vettel, who has won three of the past four races in Japan and will be aiming to clinch his fourth successive title in Sunday’s race. The German needs to win and have nearest rival Alonso finish worse than eighth.
Lotus drivers Romain Grosjean and Kimi Raikkonen finished the morning session seventh and eighth, respectively.
Hamilton’s ability to post the top time raised hopes of a more competitive race on Sunday. Vettel has won the past four GPs, and his latest victory at the Korean Grand Prix on Sunday stretched his lead over Alonso to 77 points with five races left,
Jules Bianchi ran off the track early in the first practice and collided head-on into a tire wall. The Marussia driver was unhurt but his car had to be cleared away by marshals. Williams driver Pastor Maldonado spun off the track and lost a back wheel late in the session.
Caterham driver Giedo van der Garde also slid off the track in an incident similar to Bianchi’s but managed to avoid the wall.