HOCKENHEIM, GERMANY - JULY 20: Jenson Button of Great Britain and McLaren prepares to drive during practice for the German Grand Prix at Hockenheimring on July 20, 2012 in Hockenheim, Germany. (Photo by Mark Thompson/Getty Images)

Jenson Button was fastest and his team mate Lewis Hamilton second as McLaren dominated a rain-hit opening practice for the German Grand Prix on Friday.

Intermittent showers made conditions tricky for the drivers although the rain was nothing on the scale that caused chaos at the British Grand Prix at Silverstone two weeks ago.

Valtteri Bottas crashed his Williams near the end of the session, smashing into the barriers on Turn 13 and emerging unscathed to survey the damage.

Button set the best time of one minute 16.595 seconds early in the session before the rain began while Hamilton, who will be taking part in his 100th Grand Prix on Sunday, was 0.498sec behind.

They were followed by world championship leader Fernando Alonso of Ferrari and Mercedes' Michael Schumacher. However, the conditions meant it was difficult to read anything significant into the timings.

The German Grand Prix is seen as crucial to McLaren's season after poor performances in the previous two races saw them slip down the standings.

The session was the debut for the new version of the cars following a series of upgrades.

The Red Bull pair made little impact with Sebastian Vettel 12th fastest and Mark Webber 20th. - Reuters


1 Jenson Button (Britain) McLaren - 1min16.595

2 Lewis Hamilton (Britain) McLaren - 1:17.093

3 Fernando Alonso (Spain) Ferrari - 1:17.370

4 Michael Schumacher (Germany) Mercedes - 1:17.382

5 Sergio Perez (Mexico) Sauber - 1:17.413

6 Nico Huelkenberg (Germany) Force India - 1:17.599

7 Nico Rosberg (Germany) Mercedes - 1:17.915

8 Felipe Massa (Brazil) Ferrari - 1:17.995

9 Pastor Maldonado (Venezuela) Williams - 1:18.020

10 Romain Grosjean (France) Lotus - 1:18.130

11 Kamui Kobayashi (Japan) Sauber - 1:18.226

12 Sebastian Vettel (Germany) Red Bull - 1:18.339

13 Valtteri Bottas (Finland) Williams - 1:18.422

14 Daniel Ricciardo (Australia) Toro Rosso - 1:18.709

15 Kimi Raikkonen (Finland) Lotus - 1:18.831

16 Jules Bianchi (France) Force India - 1:18.972

17 Jean-Eric Vergne (France) Toro Rosso - 1:19.039

18 Vitaly Petrov (Russia) Caterham - 1:19.674

19 Heikki Kovalainen (Finland) Caterham - 1:19.963

20 Mark Webber (Australia) RedBull - Renault 1:20.122

21 Charles Pic (France) Marussia - 1:20.169

22 Timo Glock (Germany) Marussia - 1:20.539

23 Pedro de la Rosa (Spain) Hispania - 1:21.138

24 Dani Clos (Spain) Hispania - 1:21.740