Sandy Casar, riding for the Francaise des Jeux team, recovered from a collision with a stray dog to win the 18th stage of the Tour de France from Cahors to Angoulme.

The Frenchman broke away from the pack with three other riders - Michael Boogerd, Jerome Lefevre and Frederik Willems - at the 16km point, to build a lead of over 17min. For the second time in this year's Tour a dog tried to intervene, though, and wandered onto the course, prompting Casar to crash into Willems.

While the Belgian struggled to carry on and slipped back to join the peloton, Casar found the resolve to continue his charge and soon he and Axel Merckx were allowed to join Lefevre and Boogerd at the front. Together at the 36km mark, and despite having another two category-four climbs ahead, the foursome continued to drive away.

When the peloton rose of the over the summit of the day's final climb, they were12min 25secs behind the leaders. Alberto Contador's Discovery Channel team tried to wheel them in, but after realising the task was beyond them decided to reserved their energy for tomorrow's finale.

Casar held off his breakaway partners to beat Merckx to the line by 1 sec. Contador maintained control of the yellow jersey as overall race leader and will go into the penultimate stage from Cognac to Angoulme with the title in sights. American Levi Leipheimer and Australian Cadel Evans could yet triumph however.

Stage 18 result

1. Sandy Casar, France, Francaise des Jeux, 5 hours, 13 minutes, 31 seconds.
2. Axel Merckx, Belgium, T-Mobile, 1 second behind.
3. Laurent Lefevre, France, Bouygues Telecom, same time.
4. Michael Boogerd, Netherlands, Rabobank, same time.
5. Tom Boonen, Belgium, Quick Step-Innergetic, 8:34.

Overall standings

1. Alberto Contador, Spain, Discovery Channel, 86:04:16
2. Cadel Evans, Australia, Predictor-Lotto, 1:50.
3. Levi Leipheimer, United States, Discovery Channel, 2:49.
4. Carlos Sastre, Spain, Team CSC, 6:02.
5. Haimar Zubeldia, Spain, Euskaltel-Euskadi, 6:29.