Norway's Thor Hushovd, winner of the opening prologue, sliced open his arm and bled profusely after being squeezed against the barriers that line the route in the final sprint. Hushovd may need stitches but is expected to continue, the Tour doctor said.
Hushovd had been the leader after capturing Saturday's time trial, but Hincapie picked up bonus time on a sprint section of Sunday's course. The veteran New Yorker will wear the yellow jersey for the first time Monday in the second stage of the three-week race.
Casper beat out Australia's Robbie McEwen and Germany's Erik Zabel in the finishing sprint into Strasbourg in eastern France.