Button tops first practice in Spain

A late flying lap on soft tyres saw Button beat second-placed Jarno Trulli (Toyota) by 0.355 seconds, with Robert Kubica and Nick Heidfeld third and fourth for BMW Sauber.

Despite the host of untested upgrades appearing on cars up and down the pitlane, the teams were still unwilling to waste mileage on a dusty track, so no one set a timed lap until Sebastien Bourdais took his Toro Rosso out after half an hour.

The Frenchman was quickly usurped by the two Toyotas, which took the unusual decision to start the morning on the soft tyres.

Trulli and Timo Glock repeatedly swapped the top spot during their initial runs, but were then beaten by the Felipe Massa, using the harder tyre on his Ferrari, at the session's halfway point.

Button made a quiet start to the weekend, languishing as low as 17th in the early runs, before becoming the fifth man to head the field as he beat Massa by 0.2s with 33 minutes to go.

Massa was unable to respond at first, his revised Ferrari needing attention to a front wing problem before he could resume running.

As the session neared its end, Trulli temporarily restored Toyota's superiority with a string of quick laps on hard tyres that eventually put him 0.389s clear of Button.

But Button fought back with a last minute charge on soft tyres that took him to a 1m21.799s lap, the only sub-1m22s time of the session.

Trulli held on to second, as the two BMWs jumped into the top four on soft rubber at the end.

Williams took fifth and sixth with Kazuki Nakajima and Nico Rosberg, the latter having spun at Turn 14 when on course to top the session earlier on.

Nelson Piquet said yesterday that Renault was giving him more low fuel mileage in practice to help improve his qualifying form, and that seemed to pay off as he challenged for the top five in practice and ended up seventh - ten places clear of his low-key team-mate Fernando Alonso.

Glock fell to eighth, having had a trip through the Turn 4 gravel and also messed up the final chicane on his final lap.

Massa and Brawn's Rubens Barrichello completed the top 10, with Kimi Raikkonen 11th for Ferrari.

Red Bull only managed 12th and 13th. Mark Webber went wide at the chicane on a late run, while Sebastian Vettel was fastest of all in sector one, but could not sustain that pace around the rest of the lap. He also went off the road at Turn 4 earlier on.

Pos  Driver       Team                      Time               Laps
 1.  Button       Brawn-Mercedes        (B) 1:21.799            21
 2.  Trulli       Toyota                (B) 1:22.154  + 0.355   30
 3.  Kubica       BMW-Sauber            (B) 1:22.221  + 0.422   24
 4.  Heidfeld     BMW-Sauber            (B) 1:22.658  + 0.859   14
 5.  Nakajima     Williams-Toyota       (B) 1:22.659  + 0.860   24
 6.  Rosberg      Williams-Toyota       (B) 1:22.667  + 0.868   26
 7.  Piquet       Renault               (B) 1:22.753  + 0.954   24
 8.  Glock        Toyota                (B) 1:22.828  + 1.029   29
 9.  Massa        Ferrari               (B) 1:22.855  + 1.056   15
10.  Barrichello  Brawn-Mercedes        (B) 1:22.859  + 1.060   24
11.  Raikkonen    Ferrari               (B) 1:22.873  + 1.074   20
12.  Webber       Red Bull-Renault      (B) 1:22.934  + 1.135   25
13.  Vettel       Red Bull-Renault      (B) 1:22.959  + 1.160   24
14.  Hamilton     McLaren-Mercedes      (B) 1:23.077  + 1.278   21
15.  Bourdais     Toro Rosso-Ferrari    (B) 1:23.088  + 1.289   30
16.  Fisichella   Force India-Mercedes  (B) 1:23.089  + 1.290   25
17.  Alonso       Renault               (B) 1:23.157  + 1.358   18
18.  Buemi        Toro Rosso-Ferrari    (B) 1:23.185  + 1.386   31
19.  Kovalainen   McLaren-Mercedes      (B) 1:23.522  + 1.723   17
20.  Sutil        Force India-Mercedes  (B) 1:23.536  + 1.737   19

All Timing Unofficial