Four-time Olympic champion Sir Chris Hoy came from behind to take a morale-boosting victory in the men\'s World Cup keirin as Britain continued to build towards London 2012 at the Olympic velodrome. Hoy, who won triple gold in Beijing in the sprint, team sprint and keirin, had coasted through the first round earlier Saturday and won his second round heat in which teammate Matthew Crampton crashed out. However the big Scotsman had to dig deep in a final in which New Zealand\'s Simon Van Velthooven played the upsetter by taking off with just over two laps to go. Hoy had plenty of ground to make up but after sitting tight on the wheel of Frenchman Mickael Bourgain he picked up the pace to move into contention in the final lap and squeezed the victory out at the finish. German Rene Enders finished in second with Mickael Bourgain of France in third. Hoy, racing with Ross Edgar and Jason Kenny, finished third in the men\'s team sprint on Friday -- an event in which they are the Olympic champions -- behind France and world champions Germany. Hoy\'s other Olympic gold came in the one-kilometre time trial, no longer an Olympic event, in 2004.