Fernando Alonso puts Ferrari on top in opening practice for the Spanish Grand Prix

Although the home favourite did not go for a flying lap until over an hour into the morning, Alonso was immediately quick when he finished his data-gathering runs - knocking Sebastian Vettel's Red Bull off the top spot with a 1m24.754s lap 21 minutes from the end of the session.

Alonso then improved again on his next run and lapped in 1m24.430s, giving him a 0.378-second cushion over Vettel, who remained second to the finish.

Before Alonso started setting the pace, Vettel had enjoyed a 15-minute spell at the head of the order, having usurped long-time first-place man Kamui Kobayashi. The Sauber stayed near the front, though, holding third place at the end of the session.

McLaren's practice activities included evaluating its new nose and checking sight lines with a bar across the top of the chassis. Jenson Button was fourth quickest, with team-mate Lewis Hamilton eighth.

Williams test driver Valtteri Bottas spent a while in second before ending up fifth in Bruno Senna's regular car. Michael Schumacher and Romain Grosjean were next up in the best Mercedes and Lotus respectively, with the latter's team-mate Kimi Raikkonen and Force India's Nico Hulkenberg completing the top 10 behind Hamilton.

Bottas was one of four reserve drivers in action during the morning. Jules Bianchi was 18th in Paul di Resta's Force India, and there were debuts for Caterham's Alexander Rossi and HRT's Dani Clos, who were 21st and 24th respectively. Clos' car developed a problem near the end but he was able to crawl back into the pitlane before coming to a halt at the end of the pit entry.

Pos  Driver                Team                   Time               Laps
 1.  Fernando Alonso       Ferrari                1m24.430             20
 2.  Sebastian Vettel      Red Bull-Renault       1m24.808s  + 0.378   18
 3.  Kamui Kobayashi       Sauber-Ferrari         1m24.912s  + 0.482   28
 4.  Jenson Button         McLaren-Mercedes       1m24.996s  + 0.566   24
 5.  Valtteri Bottas       Williams-Renault       1m25.120s  + 0.690   24
 6.  Michael Schumacher    Mercedes               1m25.187s  + 0.757   15
 7.  Romain Grosjean       Lotus-Renault          1m25.217s  + 0.787   16
 8.  Lewis Hamilton        McLaren-Mercedes       1m25.252s  + 0.822   20
 9.  Kimi Raikkonen        Lotus-Renault          1m25.285s  + 0.855   29
10.  Nico Hulkenberg       Force India-Mercedes   1m25.339s  + 0.909   24
11.  Jean-Eric Vergne      Toro Rosso-Ferrari     1m25.367s  + 0.937   22
12.  Felipe Massa          Ferrari                1m25.433s  + 1.003   21
13.  Mark Webber           Red Bull-Renault       1m25.539s  + 1.109   23
14.  Nico Rosberg          Mercedes               1m25.607s  + 1.177   20
15.  Sergio Perez          Sauber-Ferrari         1m25.918s  + 1.488   19
16.  Daniel Ricciardo      Toro Rosso-Ferrari     1m26.226s  + 1.796   24
17.  Pastor Maldonado      Williams-Renault       1m26.297s  + 1.867   18
18.  Jules Bianchi         Force India-Mercedes   1m26.630s  + 2.200   21
19.  Vitaly Petrov         Caterham-Renault       1m27.475s  + 3.045   20
20.  Timo Glock            Marussia-Cosworth      1m28.267s  + 3.837   21
21.  Alexander Rossi       Caterham-Renault       1m28.448s  + 4.018   25
22.  Charles Pic           Marussia-Cosworth      1m28.633s  + 4.203   22
23.  Pedro de la Rosa      HRT-Cosworth           1m29.107s  + 4.677   19
24.  Dani Clos             HRT-Cosworth           1m31.618s  + 7.188   19

All Timing Unofficial