Red Bull driver Sebastian Vettel has set the fastest time in Friday's practice ahead of the Singapore Grand Prix. With the Red Bull cars needing to finish ahead of their Brawn GP rivals Sunday to keep interest in the Formula One championship, Vettel set a best time of 1 minute, 48.650 seconds at the Marina Bay circuit. Renault driver Fernando Alonso, who won the race last year, was second fastest, ahead of McLaren driver Heikki Kovalainen and Nick Heidfeld of BMW. Championship leader Jenson Button of Brawn was fifth best, a place ahead of Red Bull driver Mark Webber, whose second practice session was curtailed by a crash into a wall. Brawn driver Rubens Barrichello was 11th. 