Bakersfield: Young Slovakian Peter Sagan won the fifth stage of the Tour of California ahead of Australian Michael Rogers, who seized the overall leader`s yellow jersey from American David Zabriskie.
The stage was marked by a crash involving American Lance Armstrong, who was forced to withdraw from the race.
Armstrong received a cut under his left eye that required eight stitches and suffered a severely bruised left elbow, his RadioShack team said.
Sagan, the 20-year-old Liquigas rider, triumphed in a sprint after a six-man breakaway fell apart and was reeled in on the finishing circuits of the 195.5km stage in Bakersfield.
Zabriskie led out the sprint after three punishing trips up the short China Grade climb. Sagan and Rogers were both on his wheel and Sagan surged past him for the stage win.
Rogers crossed the line second and claimed the yellow jersey courtesy of a time bonus from earlier in the stage.
Seven-time Tour de France champion Armstrong was the talk of the day even before the stage began, as disgraced US cyclist Floyd Landis levied new accusations of doping against his former teammate.
Landis, who had long denied doping despite being stripped of his 2006 Tour de France title after a positive test, has gone public with confessions of his own cheating and alleged that Armstrong also engaged in systematic doping.
"Floyd lost his credibility a long time ago," Armstrong told a clutch of reporters prior to the start of the stage in Visalia, California.
"We have nothing to hide. We have nothing to run from."
Armstrong had gone into the fifth stage in 16th place overall, 27 seconds off the lead. After his fall he attempted to continue, but called it a day as his eye swelled shut.
"I tried to give it a go but my eye was swollen so I couldn`t see properly and the pain in the elbow prevented me from holding the bars for the remainder of the stage," he said.
Armstrong said he would take a few days off, and resume training as quickly as possible. Prior to the Tour de France (July 3-25), Armstrong is slated to race in the Tour of Switzerland which starts on June 12.
The Tour of California continues Friday with the 217.7km sixth stage from Palmdale to Big Bear Lake. The race concludes on Sunday.