VALENCIENNES, France -- Tour de France leader Rolf Sorensen of Denmark broke his collarbone in a fall near the finish of Wednesday's fifth stage and likely will be forced to withdraw.
His withdrawal would put American Greg LeMond, a three-time winner of the event, in the overall lead.
Sorensen was in a group of riders in a fall about 2 miles (3 km) from the finish of the 93-mile stage from Reims to Valenciennes. He was given another bicycle by teammate Bruno Cenghialta and finished the stage, holding his shoulder.
The 26-year-old rider was rushed by ambulance to a local hospital from the finish line. X-rays confirmed the fracture, said Dr. Gerard Nicolet, one of the physicians on the race staff.
'I can't see him going on,' Nicolet said.
Giancarlo Feretti, director of Sorensen's Ariostea team, said Sorensen would have to quit the race. The rider was expected to travel Thursdayto Italy for medical treatment.
'It could require surgery,' Ferretti said.
Sorensen still held the overall lead at the close of the day, nine seconds ahead of LeMond and 10 seconds ahead of Ireland's Sean Kelly. But his probable absence from the sixth stage would leave LeMond with the lead and the yellow jersey.
'If it is confirmed that Sorensen has to go out, LeMond would start in front,' race director Jean-Marie LeBlanc said.
Dr. Gerard Porte, chief physician for the race, said Sorensen's injuries, which also included cuts and scrapes to the head, left knee and left elbow, would prevent him from resuming the 2,449-mile (3,940 km) race.
'He wanted to continue, but I advised him against it, as did his team director,' Porte said.
The accident comes as a blow to Sorensen, who said wearing the yellow jersey was the realization of a dream.
'It's a tragedy,' LeBlanc said. 'Sorensen and his team showed a lot of class. He was extremely proud of the yellow jersey.
'There was a spectacular finish, and in that situation there are risks. The leader paid the price, unfortunately for the Tour de France.'
Jelle Nijdam of Holland won the 93-mile (149.5 km) fifth stage from Reims to Valenciennes in a time of 3 hours, 17 minutes, 38 seconds. Nijdam managed to break ahead of the pack in the last mile to cross the line a few yards ahead of German sprint specialists Remig Stumpf and Olaf Ludwig.
LeMond finished eight seconds behind Nijdam, with Sorensen another second back. Steve Bauer of Canada finished the stage in the pack one second behind Nijdam and was 44th overall, 2:30 behind Sorensen.
The stage was highlighted by a failed breakaway attempt by Italian rider Claudio Chiappucci some 3 miles (5 km) from the finish. LeMond's Z team, however, successfully closed the gap just before the finish.
'I alerted the guys,' Z team member Eric Boyer said. 'We didn't lose our cool. we just got organized and accelerated. You can't get too worked up about a breakaway if it's far from the finish.'
Chiappucci conceded that he began his move too soon.
'I wanted to try it today,' he said. 'If I had been closer to the finish, it would have worked.'
Djamolidine Abdoujaparov of the Soviet Union won Tuesday's 180-mile trip from Dijon to Reims, the longest stage of the 23-day event, with a final sprint.
Sorensen took the overall lead from LeMond during Sunday's second stage, a 22.6-mile team time trial. LeMond, attempting to win his third straight Tour de France, owned the lead after Sunday morning's opening stage -- a 71.3-mile loop around Lyon.
The Tour de France will conclude July 28 on the Champs Elysees in Paris. A total of 184 riders originally entered the race, which consists this year of 80 miles of individual time trials and only four tough mountain stages.