Singapore, Sep 25 (DPA) Rubens Barrichello was fastest in the first free practice Friday for Sunday's Singapore Formula One Grand Prix in a session that was red-flagged after a crash involving Renault driver Romain Grosjean.

The Brawn GP driver, who has won two of the last three F1 races this season to keep his championship hopes alive, registered a time of 1 minute 50.179 seconds for the 5.073-kilometre circuit.

Championship leader and teammate Jenson Button was second fastest, 0.177 seconds slower than the veteran Brazilian with Red Bull's Mark Webber third quickest.

In an eventful session, French driver Grosjean crashed into a wall coming out of Turn 14 after 41 minutes before rolling into the opposite wall but was able to get out of his car uninjured.