Alonso quickest in opening practice
Ferrari's Fernando Alonso was fastest in the opening practice session for the Spanish Grand Prix, edging Formula One points leader Sebastian Vettel of Red Bull on Friday.
The Spanish driver's lap time of 1 minute, 24.430 seconds around the Catalunya Circuit was nearly four-tenths of a second quicker than two-time defending champion Vettel, who won the race last year.
Kamui Koboyashi of Sauber was the only other driver within half a second of Alonso, with Jenson Button of McLaren and Valtteri Bottas of Williams rounding out the top five.
Ten drivers were within one second of Alonso's lap time, including Michael Schumacher, Lewis Hamilton and Kimi Raikkonen.
Following the Bahrain GP, Vettel leads Hamilton by four points in the standings coming into the first race of the European swing, with Mark Webber trailing his Red Bull teammate by five points in the standings. Webber was 13th quickest with a lap of 1:25.433.
Button and Alonso both trail Vettel by 10 points.
Felipe Massa of Ferrari was 12th and Nico Rosberg of Mercedes was 14th ahead of Sergio Perez of Sauber.
Alexander Rossi was the first American driver on F1's grid in five years as he tested for Caterham. Aside from swerving off track in one instance, the 20-year-old Rossi ran an error-free 25 laps, registering a best lap of 1:28.448.
Spanish team HRT managed to get both of its Spanish drivers out on track as Pedro de la Rosa and Dani Clos filled out the bottom two of the 24-car field, with Clos making his 2012 debut.
Testing continues with a second session later Friday before resuming on Saturday ahead of qualifying for Sunday's 66-lap race.
1. Fernando Alonso (Spain) Ferrari 1:24.430
2. Sebastian Vettel (Germany) Red Bull 1:24.808
3. Kamui Kobayashi (Japan) Sauber 1:24.912
4. Jenson Button (Britain) McLaren 1:24.996
5. Valtteri Bottas (Finland) Williams 1:25.120
6. Michael Schumacher (Germany) Mercedes 1:25.187
7. Romain Grosjean (France) Lotus 1:25.217
8. Lewis Hamilton (Britain) McLaren 1:25.252
9. Kimi Raikkonen (Finland) Lotus 1:25.285
10. Nico Huelkenberg (Germany) Force India 1:25.339
11. Jean-Eric Vergne (France) Toro Rosso 1:25.367
12. Felipe Massa (Brazil) Ferrari 1:25.433
13. Mark Webber (Australia) Red Bull 1:25.539
14. Nico Rosberg (Germany) Mercedes 1:25.607
15. Sergio Perez (Mexico) Sauber 1:25.918
16. Daniel Ricciardo (Australia) Toro Rosso 1:26.226
17. Pastor Maldonado (Venezuela) Williams 1:26.297
18. Jules Bianchi (France) Force India 1:26.630
19. Vitaly Petrov (Russia) Caterham 1:27.475
20. Timo Glock (Germany) Marussia 1:28.267
21. Alexander Rossi (U.S.) Caterham 1:28.448
22. Charles Pic (France) Marussia 1:28.633
23. Pedro de la Rosa (Spain) HRT 1:29.107
24. Dani Clos (Spain) HRT 1:31.618