Red Bull Racing came to the fore in Friday's second practice session as Sebastian Vettel and Mark Webber set the pace at the Barcelona circuit.
Vettel, using the softer option Bridgestone rubber, put in a blinder, clocking a 1:19.965 to edge his Red Bull team-mate by 0.210s.
As for third place, that again went to Michael Schumacher with the German's lap time hinting that he's a lot happier with the updated Merc GP than he was with its predecessor.
Home-town favourite Fernando Alonso was fourth ahead of Lewis Hamilton, Robert Kubica, Nico Rosberg and Felipe Massa.
Report: Installation laps got underway under dark clouds and with the track temperature sitting at 26'C. Immediately Kamui Kobayashi and Pedro de la Rosa continued on with the Japanese driver posting a 1:23.385 while de la Rosa, who did not set a time in Practice One due to a gearbox issue, took second place.
Robert Kubica dethroned the Sauber drivers before Vitaly Petrov moved ahead of his Renault team-mate with a 1:22.531. However, his reign was short-lived as Kubica went quicker still with a 1:21.937, Adrian Sutil improved to second and Kobayashi to third.
Michael Schumacher was the first of the big names out on track, hoping for a much better showing in his revised Merc GP. The German, though, lost time in the final sector and had to settle for second place behind Kubica, 0.025s down. Schumacher made amends on the following lap, taking first place by 6/10ths. Jenson Button slotted in to second place with Nico Rosberg third quickest, 0.364s behind his team-mate.
Felipe Massa claimed sixth place for Ferrari, behind Kubica and Sutil. Massa improved to fifth, Mark Webber took seventh before claiming the P1 slot, 0.050s up on Schumacher's best. Problems for Fernando Alonso as he loses a piece of bodywork on his way to 16th place. Lewis Hamilton went second.
The session, though, was red flagged as Nico Hulkenberg smashed into the barriers at Campsa corner. The rookie racer ran wide coming round Turn Nine but instead of letting up continued full throttle into the barriers on the opposite side of the track, causing major damage to his Williams. The session was stopped for 14 minutes due to the massive damage to the tyre barrier, which took the marshals some time to fix.
With practice green-flagged all the drivers, excluding Hulkenberg and Bruno Senna, ventured out, putting in the mileage as they chased that perfect set-up, evaluated the different compounds and tried to work their way up the timesheets - and all this before the rain comes down.
Massa climbed to seventh place before being dropped one as Alonso took fifth, Kubica went ninth and Hulkenberg's car was delivered back to the team covered from prying eyes. Massa continued lapping, taking second place, 0.239s behind Webber, who himself found some added pace and shaved 0.888s off his P1 time.
Schumacher was the next to climb the timesheets, taking second off his former Ferrari team-mate before Alonso followed suit and relegated Massa to fourth place only for the Brazilian to then lose out to Rosberg. Kubica improved to fourth place.
With the softer option rubber, Vettel crossed the line with a 1:19.965, taking the P1 slot by 0.210s ahead of his team-mate Webber. At the back of the pack, Jarno Trulli led Heikki Kovalainen, Karun Chandhok, Lucas di Grassi, Bruno Senna and Glock.
Three minutes remaining and Jaime Alguersuari put paid to many final runs for the chequered flag as he brought out the yellows when he stopped on the circuit with smoke and a few flames coming from the back of his Toro Rosso.
The chequered flag was waved with Vettel ahead of team-mate Webber and, for the second successive session, Schumacher was third.
01. Vettel Red Bull-Renault 1:19.965 24 laps
02. Webber Red Bull-Renault 1:20.175 + 0.210 35 laps
03. Schumacher Mercedes 1:20.757 + 0.792 28 laps
04. Alonso Ferrari 1:20.819 + 0.854 30 laps
05. Hamilton McLaren-Mercedes 1:21.191 + 1.226 23 laps
06. Kubica Renault 1:21.202 + 1.237 36 laps
07. Rosberg Mercedes 1:21.271 + 1.306 27 laps
08. Massa Ferrari 1:21.302 + 1.337 25 laps
09. Button McLaren-Mercedes 1:21.364 + 1.399 26 laps
10. Sutil Force India-Mercedes 1:21.518 + 1.553 32 laps
11. de la Rosa Sauber-Ferrari 1:21.672 + 1.707 37 laps
12. Liuzzi Force India-Mercedes 1:21.904 + 1.939 32 laps
13. Kobayashi Sauber-Ferrari 1:21.931 + 1.966 29 laps
14. Buemi Toro Rosso-Ferrari 1:22.184 + 2.219 37 laps
15. Barrichello Williams-Cosworth 1:22.192 + 2.227 33 laps
16. Petrov Renault 1:22.435 + 2.470 35 laps
17. Alguersuari Toro Rosso-Ferrari 1:22.449 + 2.484 34 laps
18. Hulkenberg Williams-Cosworth 1:23.765 + 3.800 7 laps
19. Trulli Lotus-Cosworth 1:24.209 + 4.244 26 laps
20. Kovalainen Lotus-Cosworth 1:24.894 + 4.929 22 laps
21. di Grassi Virgin-Cosworth 1:25.066 + 5.101 30 laps
22. Chandhok HRT-Cosworth 1:25.972 + 6.007 23 laps
23. Senna HRT-Cosworth 1:26.152 + 6.187 25 laps
24. Glock Virgin-Cosworth 1:26.596 + 6.631 21 laps