World champion Sebastian Vettel grabbed the quickest time with his last run in the Indian Grand Prix's final free practice on Saturday.
In smoggy conditions, Vettel clocked 1min 24.824sec to pip McLaren's Jenson Button, with his Red Bull team-mate Mark Webber third fastest ahead of Lewis Hamilton and Ferrari's Fernando Alonso.
Victory at India's first grand prix would keep Vettel on course to equal fellow German Michael Schumacher's achievement of winning 13 grands prix in one season. Vettel, 24, has 10 wins with three races remaining.
Button, Webber, Hamilton and Alonso are all vying for second spot in the standings after Vettel reclaimed his Formula One crown in Japan earlier this month.
India is hosting its inaugural Formula One race at the purpose-built Buddh International Circuit near New Delhi.
Free practice times at the Indian Grand Prix on Saturday:
1. Sebastian Vettel (GER) Red Bull 1:24.824, 2. Jenson Button (GBR) McLaren 1:25.191, 3. Mark Webber (AUS) Red Bull 1:25.203, 4. Lewis Hamilton (GBR) McLaren 1:25.288, 5. Fernando Alonso (ESP) Ferrari 1:25.784, 6. Felipe Massa (BRA) Ferrari 1:26.058, 7. Paul di Resta (SCO) Force India 1:26.785, 8. Nico Rosberg (GER) Mercedes GP 1:26.873, 9. Adrian Sutil (GER) Force India 1:26.958, 10. Sebastien Buemi (SUI) Toro Rosso 1:27.146, 11. Michael Schumacher (GER) Mercedes GP 1:27.217, 12. Bruno Senna (BRA) Lotus-Renault 1:27.235, 13. Kamui Kobayashi (JPN) Sauber 1:27.262, 14. Vitaly Petrov (RUS) Lotus-Renault 1:27.280, 15. Jaime Alguersuari (ESP) Toro Rosso 1:27.387, 16. Sergio Perez (MEX) Sauber 1:27.749, 17. Pastor Maldonado (VEN) Williams F1 1:27.793, 18. Rubens Barrichello (BRA) Williams F1 1:27.875, 19. Jarno Trulli (ITA) Lotus 1:29.355, 20. Heikki Kovalainen (FIN) Lotus 1:29.750, 21. Timo Glock (GER) Virgin Racing 1:30.683, 22. Narain Karthikeyan (IND) Hispania 1:30.900, 23. Jerome d'Ambrosio (BEL) Virgin Racing 1:32.851, 24. Daniel Ricciardo (AUS) Hispania 1:33.246