McLaren looked like they could again be the team to beat as Jenson Button and Lewis Hamilton led the way in first practice for Sunday's Japanese Grand Prix at Suzuka.
McLaren have won three of the last four races, and would almost certainly have won last time out in Singapore had Hamilton not ground to a halt with a gearbox problem while leading, and they were on the pace once more here.
Hamilton, who leaves for Mercedes at the end of the season, is looking to close a 52-point gap to championship leader Fernando Alonso, but it was team-mate Button, who has to take a five-place grid penalty this weekend, who topped the timesheets.
The 2009 world champion took 55 minutes to set a timed lap, but his second flying effort of one minute and 34.507 seconds moved him to the head of the leaderboard, where he remained for the rest of the session.
Hamilton had set the early pace, and ended Friday morning running just over two-tenths down on his compatriot. Mark Webber was the quickest of the Red Bulls in third, with team-mate Sebastian Vettel down in 17th.
Nico Rosberg gave future team-mate Hamilton a reminder of his speed with the fourth fastest time, but was forced to park his car at the Esses with a technical problem late in the session.
Michael Schumacher, fresh from announcing he will retire at the season's end, was fifth. The German had vowed to give his all over the final six races of the season and he was certainly exploring his limits, correcting a big slide after dropping a wheel on the grass on the entry to the Degner curves, before having a trip across the chicane.
Home favourite Kamui Kobayashi delighted the expectant crowd with the sixth best time, while Felipe Massa was the top Ferrari in seventh, with the Italian team once again looking short of pace as Alonso languished in 11th place.
Paul di Resta and Nico Hulkenberg were eighth and ninth for Force India, with Pastor Maldonado 10th for Williams and new McLaren signing Sergio Perez 12th for Sauber after a wild moment through the high-speed 130R corner.
Kimi Raikkonen, running a new double DRS device on his Lotus, was 13th, ahead of team-mate Romain Grosjean, who enjoyed several excursions as the teams got to grips with the hard compound Pirelli tyres. The softs were likely to be evaluated during the second practice session later on Friday.