World champion Tom Boonen stepped off his bike 59 km from the finish of the 15th stage over 187 km from Gap to l'Alpe d'Huez.
Belgian Tom Boonen clinched his first win in two years on the Tour de France when he took the race's sixth stage, a 199.5-km ride from Semur-en-Auxois to Bourg-en-Bresse on Friday.
Australian Robbie McEwen recovered from a crash to clinch the first stage of the Tour de France.
Overall leader Tom Boonen finished fifth to retain the yellow jersey after the 207-km fourth stage of the Tour de France.