Crash claims another top rider; Belgium's Boonen wears yellow

VALKENBURG, Netherlands -- Wheels touch. Bikes and riders go down. A bone breaks. Tour de France over.

So it went for Alejandro Valverde during an accident-strewn third stage Tuesday. The Spaniard, whom Lance Armstrong once said could be cycling's next big thing, fractured his right collarbone, taking yet another favorite out of the showpiece race that already lost its top contenders to a doping scandal even before it began.

On the road, there was a new overall leader, Tom Boonen, who donned the Tour's yellow jersey over the rainbow-striped world champion's shirt he already owns. Matthias Kessler of Germany won the hilly stage that covered three countries -- Luxembourg, Belgium and the Netherlands. It was the first stage victory in four tours for Kessler.

Boonen will wear yellow in his native Belgium in today's stage four.

He holds a one-second lead over Australian Michael Rogers, the world time trial champion. American George Hincapie is third.