McLaren's title challenger Kimi Raikkonen set the pace in final practice for Sunday's inaugural Turkish Grand Prix in Istanbul.
The Finn, winner of the last race in Hungary and 26 points adrift of Renault's Formula One leader Fernando Alonso with six rounds remaining, roared around the Istanbul Park circuit on Saturday in one minute 26.120 seconds.
Mercedes-powered McLaren again looked the team to beat, with Colombian Juan Pablo Montoya top of the timesheets in the first of the day's two 45 minute sessions, with BAR and Renault running close behind.
Briton Jenson Button shut out the continuing uncertainty about his future, with BAR hoping to retain him next year despite his contract with Williams, to set the second quickest time in both sessions.
Alonso, chasing his seventh win of the season, was third.
The times were slower than in Friday's second practice session when Montoya was the leading race driver behind Toyota test driver Ricardo Zonta and McLaren's Spanish reserve Pedro de la Rosa.
While Raikkonen can only hope to rein in Alonso in Turkey, McLaren are far closer in the constructors' standings with just 12 points between them.
Ferrari's world champion Michael Schumacher again looked out of sorts on the anti-clockwise circuit in a clear and sunny session after morning mist.
The German was 14th in both sessions.
"I think the impression I formed of this track after riding around it on a scooter was misleading," the 36-year-old, who is one pole position off Ayrton Senna's record, had said on Friday.
"I thought it did not seem that difficult but now, in the car with a much lower seating position, it looks very different.
"Some corners, such as turn one, have a blind exit which makes it very interesting."
India's Jordan driver Narain Karthikeyan only managed an out lap before he had to return to the pits after his car was affected by technical problems.
Timings from the second free practice session 2:
1. Kimi Raikkonen (Finland) McLaren 1:26.120
2. Jenson Button (Britain) BAR 1:26.599
3. Fernando Alonso (Spain) Renault 1:26.627
4. Juan Pablo Montoya (Colombia) McLaren 1:26.748
5. Giancarlo Fisichella (Italy) Renault 1:27.240
6. Takuma Sato (Japan) BAR 1:27.308
7. Mark Webber (Australia) Williams 1:27.335
8. Ralf Schumacher (Germany) Toyota 1:27.556
9. David Coulthard (Britain) Red Bull 1:27.796
10. Felipe Massa (Brazil) Sauber 1:27.829
11. Christian Klien (Austria) Red Bull 1:27.919
12. Jarno Trulli (Italy) Toyota 1:27.921
13. Nick Heidfeld (Germany) Williams 1:27.951
14. Michael Schumacher (Germany) Ferrari 1:28.155
15. Jacques Villeneuve (Canada) Sauber 1:28.534
16. Rubens Barrichello (Brazil) Ferrari 1:28.615
17. Tiago Monteiro (Portugal) Jordan 1:28.830
18. Robert Doornbos (Netherlands) Minardi 1:30.155
19. Christijan Albers (Netherlands) Minardi 1:30.999
20. Narain Karthikeyan (India) Jordan
