Vettel fastest in Singapore GP practice

Formula One championship leader Sebastian Vettel signaled he is on course to clinch the title this weekend by setting the fastest time in Fridays practice sessions for the Singapore Grand Prix.The Red Bull driver was two tenths of a second quicker than Ferraris Fernando Alonso in the second session, with McLarens Lewis Hamilton third fastest as the top three teams dominated.Ferraris Felipe Massa was fourth quickest around Marina Bay, with Red Bulls Mark Webber fifth and Mercedes Michael Schumacher sixth.Jenson Buttons second session came to an end early after he failed to negotiate a turn and unable to select reverse gear was forced to leave his McLaren car parked on the circuit.Vettel leads the championship by 112 points and if he gathers 13 points more than his closest rival Alonso on Sunday, then he would have successfully defended his title with five races to spare.I feel its a weekend where we have a good car, looks like its a competitive car to be able to fight for the podium, Vettel said. We still have to make adjustments overnight and do our homework.While Vettel was not prepared to be too bullish looking ahead to Sunday, Hamilton acknowledged that Fridays performance shows the German will again be hard to beat.Alonso said Ferraris good pace on long runs and the fast rate of tire degradation on the bumpy and abrasive street circuit should benefit his team.We may have an opportunity, Alonso said.Toro Rosso driver Sebastien Buemi collided with one of the concrete barriers that hems in the tight street circuit, snapping the front right suspension.Force Indias Adrian Sutil was seventh fastest while his teammate Paul di Resta had little running due to a brake and hydraulic problem that had his car being rebuilt for much of the session.The Sauber pair of Sergio Perez and Kamui Kobayashi were eighth and ninth on the timesheets, with Button in 10th.