One day Peter Sagan was twirling his fingers and celebrating victory.
A day later, the world champion from Slovakia — one of the sport's biggest stars — was disqualified from the Tour de France.
Sagan was sent home Tuesday for causing a serious crash in a chaotic sprint finish that left Mark Cavendish needing treatment for his injuries and further examinations in a hospital.
About 54 yards from the end of stage 4, Sagan elbowed Cavendish, who was squeezed against the barriers to his right, out of the way.
Cavendish slammed into the barriers and two other riders plowed over the British sprint specialist, a winner of 30 Tour stages.
"We have decided to...