Nico Rosberg set the fastest time of the day in Friday's second free practice session for the Bahrain Grand Prix, as the German continued his tradition of setting a blistering practice pace in 2009.
The Williams man's 1m33.339s lap was nearly two tenths faster than Renault's Fernando Alonso could manage, while Jarno Trulli ended the day third quickest.
Jenson Button was the first big gun to set a time in the second 90 minutes, as the World Championship leader lapped Sakhir in a 1m35.935s. It wasn't long before the Briton was usurped, first by Force India's Giancarlo Fisichella, and then more significantly, by the two Toyota drivers.
Timo Glock and Trulli, both on the super-soft option Bridgestone slicks, swapped places at the top of time for a large portion of the session with the Italian's lap of 1m33.616 finally settling the issue between them. But neither could do anything about Rosberg's Williams when the German thumped in his best lap with just 20 minutes to go.
Then in the closing stages, Alonso, having spent most of the day on heavy fuel, banged in a very quick 1m33.530s to go second, having set the fastest first and third sectors.
Last weekend's winner Sebastian Vettel and his Red Bull teammate Mark Webber moved into contention with fourth and fifth in the last 15 minutes of the season, ahead of Button and an impressive Adrian Sutil. Glock was eventually pushed down to eighth.
Rubens Barrichello and Kazuki Nakajima completed the top 10, while World Champion Lewis Hamilton ended the day 11th.
Felipe Massa – not running KERS – was the fastest Ferrari driver in 16th, while two places back was Kimi Raikkonen, the pair split by Robert Kubica's BMW.
There was again several instances of drivers running over the curbs at Turn 1 and Turn 10, while Renault's Nelson Piquet was forced to pit early on for a broken front wing before finally ending the session 15th.PRACTICE RESULTS:
Pos Driver Team Time LapsRelated stories:Hamilton tops opening practice in BahrainRosberg sure of positive Bahrain weekendRosberg: Better times ahead
1. Rosberg Williams-Toyota (B) 1:33.339 36
2. Alonso Renault (B) 1:33.530 + 0.191 25
3. Trulli Toyota (B) 1:33.616 + 0.277 37
4. Vettel Red Bull-Renault (B) 1:33.661 + 0.322 29
5. Webber Red Bull-Renault (B) 1:33.676 + 0.337 32
6. Button Brawn-Mercedes (B) 1:33.694 + 0.355 35
7. Sutil Force India-Mercedes (B) 1:33.763 + 0.424 30
8. Glock Toyota (B) 1:33.764 + 0.425 37
9. Barrichello Brawn-Mercedes (B) 1:33.885 + 0.546 30
10. Nakajima Williams-Toyota (B) 1:33.899 + 0.560 36
11. Hamilton McLaren-Mercedes (B) 1:33.994 + 0.655 30
12. Fisichella Force India-Mercedes (B) 1:34.025 + 0.686 23
13. Buemi Toro Rosso-Ferrari (B) 1:34.127 + 0.788 37
14. Bourdais Toro Rosso-Ferrari (B) 1:34.366 + 1.027 26
15. Piquet Renault (B) 1:34.411 + 1.072 29
16. Massa Ferrari (B) 1:34.564 + 1.225 34
17. Kubica BMW-Sauber (B) 1:34.605 + 1.266 31
18. Raikkonen Ferrari (B) 1:34.670 + 1.331 28
19. Kovalainen McLaren-Mercedes (B) 1:34.764 + 1.425 35
20. Heidfeld BMW-Sauber (B) 1:34.790 + 1.451 33
All Timing Unofficial