Nico Rosberg experienced both pace and problems in Friday's second practice in Spain as the Williams driver set the pace before breaking down.
Rosberg, who has often topped the timesheets in this season's practice sessions, posted a 1:21.588 to beat his team-mate Kazuki Nakajima to the P1 slot. But, moments before the end of the session, the German was forced to park his Williams on the side of the track as he suffered a technical problem.
Third place went to hometown favourite Fernando Alonso.
Report: With cloud cover building overhead, the second practice session for the Spanish GP got underway at the Circuit de Catalunya on Friday afternoon. Bad news for Adrian Sutil, his Force India suffered a fuel cell problem and as that takes roughly six hours to replace the German would be forced to sit out the session.
Sebastian Vettel, Jarno Trulli and Nico Rosberg got proceedings underway with the former setting the first lap time of the day, a 1:26.109. Attention, though, quickly shifted to Seb Buemi, who stopped out on track with the rear of his car literally on fire.
Vettel's time was beaten by Nico Rosberg before a whole host of drivers overtook the two with Robert Kubica taking the P1 slot followed by Nelson Piquet and Mark Webber. Piquet continued lapping and was the next driver up into the P1 slot before once again being beaten by Kubica. Ferando Alonso took third place. Timo Glock joined the tussle hitting the front before Piquet took it off him.
The arrival of Brawn GP's Rubens Barrichello saw another party join the battle as he went quickest with a 1.23.348. Meanwhile Felipe Massa was complaining to Ferrari about his set-up as the Brazilian ran wide at Turn 9. He was down in 13th place with 16 runners having set times. His team-mate Kimi Raikkonen went 12th while Lewis Hamilton was fifth quickest.
Jenson Button overhauled Barrichello for first place with a 1:23.057 with Vettel, Rosberg, Piquet, Glock, Hamilton and Alonso completing the top eight. Alonso moved up a place to seventh while his team-mate Piquet went quickest of all. Kazuki Nakajima upped his pace to take the P1 slot off Piquet while Timo Glock pushed hard - and right off the track at Turn 2.
Webber improved to fourth place while Kimi Raikkonen found himself down in 16th as the Finn struggled to get any pace out of his heavily modified F60. Webber went on to take second place but was dropped when his team-mate Vettel went quickest.
Massa moved up to 14th place, Heikki Kovalainen 16th and Hamilton ninth. The latter, though, appeared to lose a piece of bodywork off his car as he swept through Turn 9.
Nakajima, using the softer option tyres, moved to the front of the pack with a 1:21.805, over half a second up on Vettel's time. Raikkonen, meanwhile, had yet another KERS problem as he moves up to 10th place. Kovalainen, putting on the softer Bridgestone tyres, moved up to 11th place.
Problems for Piquet, who got sidewards coming into corner at Turn 9 and gently touched the barrier with his R29. Thankfully he went sidewards across the gravel, which took the speed off the car and saved it from serious damage.
Barrichello took second place with Giancarlo Fisichella putting his Force India into the top ten with an impressive run. Both Ferraris improve with Massa taking 10th place and Raikkonen 13th. Alonso moved up to third place but was dropped as Rosberg took the P1 slot off his team-mate.
Buemi made his way back onto the track for the final 15 minutes but after running wide twice he quickly made his way back into the Toro Rosso garage. His team-mate Bourdais improved to ninth place after setting a personal best second sector time.
Rosberg lowered the benchmark time to a 1.21.588 as Williams continue to dominate in the latter stages of the session. The German's session, though, came to a premature end as he stopped out on track in the final minute of the session.
He did, however, still finish at the top of the timesheets ahead of Nakajima and Alonso.
1. Rosberg Williams-Toyota 1:21.588 43 laps
2. Nakajima Williams-Toyota 1:21.740 + 0.152 40 laps
3. Alonso Renault 1:21.781 + 0.193 36 laps
4. Barrichello Brawn-Mercedes 1:21.843 + 0.255 39 laps
5. Webber Red Bull-Renault 1:22.027 + 0.439 37 laps
6. Button Brawn-Mercedes 1:22.052 + 0.464 35 laps
7. Vettel Red Bull-Renault 1:22.082 + 0.494 45 laps
8. Piquet Renault 1:22.349 + 0.761 26 laps
9. Buemi Toro Rosso-Ferrari 1:22.571 + 0.983 17 laps
10. Raikkonen Ferrari 1:22.599 + 1.011 40 laps
11. Bourdais Toro Rosso-Ferrari 1:22.615 + 1.027 30 laps
12. Fisichella Force India-Mercedes 1:22.670 + 1.082 32 laps
13. Hamilton McLaren-Mercedes 1:22.809 + 1.221 31 laps
14. Kovalainen McLaren-Mercedes 1:22.876 + 1.288 29 laps
15. Massa Ferrari 1:22.878 + 1.290 35 laps
16. Kubica BMW-Sauber 1:22.948 + 1.360 40 laps
17. Heidfeld BMW-Sauber 1:23.173 + 1.585 39 laps
18. Glock Toyota 1:23.360 + 1.772 46 laps
19. Trulli Toyota 1:23.623 + 2.035 47 laps
20. Sutil Force India
Source : Planet F1