Sakhir, Bahrain - Lewis Hamilton led from Nick Heidfeld and Robert Kubica as McLaren-Mercedes and BMW Sauber got a much-needed boost on Friday in the first practice session for the Bahrain Formula One Grand Prix.

The world champion Hamilton posted 1 minute 33.647 points for the 5.451-kilometres lap on the Bahrain International Circuit in his McLaren.

Germany's Heidfeld and Kubica of Poland drove their BMWs to 1:33.907 and 1:33.938, seconds, respectively.

World championship leader Jenson Button of Britain was fifth in 1:34.434 in his Brawn GP while Red Bull driver Sebastian Vettel, the winner in rainy China last Sunday, came 12th in 1:34.938 minutes.

Button leads the championship from two wins and one third place with 21 points from Brazilian team-mate Rubens Barrichello (15).

The Briton Hamilton, by contrast, has just four points as McLaren have had a difficult start into the season. That also applies to BMW, who have four points from Heidfeld's fifth-place finish in Malaysia.

Even worse off are Ferrari who are on zero points. But the eighth-place finish of Felipe Massa on Friday may be a glimmer of hope for the Italian team. The Brazilian won the last two Bahrain races.

A second practice session was scheduled for later Friday, which will likely give a better indication of the pecking order for Saturday's qualifying and the fourth race of the season set on Sunday.