SUZUKA, Japan, Oct 5, 2012 (AFP) - Britain's Jenson Button headed his departing McLaren team-mate Lewis Hamilton in opening free practice for the Japanese Grand Prix on Friday.
In fine and sunny conditions, Button, 32, who has started from pole position just once this season, clocked a time of one minute 34.507 seconds in the 90-minute session to lead the 24-car field.
Second fastest was Hamilton, who this week announced he will move to Mercedes for the 2013 season. Hamilton was 0.233 seconds slower than Button but one-tenth quicker than Australia's Mark Webber in his Red Bull.
Fourth fastest was Nico Rosberg, who pulled his Mercedes to a stop at the trackside in the last minute. His team-mate Michael Schumacher, the seven-time world champion who announced his retirement Thursday, placed fifth.
Sixth was local favourite Kamui Kobayashi in the Sauber, followed by Brazil's Felipe Massa in the first of the Ferraris.
Force India duo Paul di Resta and Nico Hulkenberg finished eighth and ninth respectively while Venezuelan driver Pastor Maldonado completed the top 10 in his Williams.
Current world championship leader Fernando Alonso of Ferrari was 11th with his nearest challenger in the title race, Red Bull's Sebastian Vettel, 17th.
.1. Jenson Button (GBR/McLaren MP4-27) 1:34.507 .2. Lewis Hamilton (GBR/McLaren MP4-27) 1:34.740 .3. Mark Webber (AUS/Reb Bull RB8) 1:34.856 .4. Nico Rosberg (GER/Mercedes F1 W03) 1:35.059 .5. Michael Schumacher (GER/Mercedes F1 W03) 1:35.122 .6. Kamui Kobayashi (JPN/Sauber C31) 1:35.199 .7. Felipe Massa (BRA/Ferrari F2012) 1:35.283 .8. Paul di Resta (GBR/Force India VJM05) 1:35.299 .9. Niko Hülkenberg (GER/Force India VJM05) 1:35.474 10. Pastor Maldonado (VEN/Williams FW34) 1:35.478 11. Fernando Alonso (ESP/Ferrari F2012) 1:35.484 12. Sergio Pérez (MEX/Sauber C31) 1:35.584 13. Kimi Raikkonen (FIN/Lotus E20) 1:35.691 14. Romain Grosjean (FRA/Lotus E20) 1:35.724 15. Daniel Ricciardo (AUS/Toro Rosso STR7) 1:36.123 16. Jean-Eric Vergne (FRA/Toro Rosso STR7) 1:36.222 17. Sebastian Vettel (GER/Red Bull RB8) 1:36.366 18. Valtteri Bottas (FIN/Williams FW34) 1:36.389 19. Timo Glock (GER/Marussia MR01) 1:37.716 20. Vitaly Petrov (RUS/Caterhan CT01) 1:38.295 21. Charles Pic (FRA/Marussia MR01) 1:38.616 22. Narain Karthikeyan (IND/HRT 112) 1:39.043 23. Giedo Van der Garde (HOL/Caterham CT01) 1:39.374 24. Pedro de la Rosa (ESP/HRT 112) 1:39.688