CHERASCO, Italy -- Mark Cavendish sprinted to victory in the 13th and longest stage of the Giro dItalia on Friday, and favourite Vincenzo Nibali retained the overall lead to boost his chances of a first victory in his home countrys biggest cycling race. Tour de France winner Bradley Wiggins and defending champion Ryder Hesjedal withdrew from the race before the stage began. Wigginss team cited a "worsening chest infection." Hesjedal is more than 32 minutes behind and his team says he pulled out because of a "deteriorating physical condition." Cavendish won in a time of 6 hours, 9 minutes, 55 seconds to claim a second straight stage victory and the fourth in this years Giro. The Briton was, as always, quick to praise his Omega Pharma team. "Im so tired, I dont know how Im going to recover from this before the mountains," Cavendish said. "Its a common misconception that sprinters are lazy. But the amount of effort it takes to do that, especially when youre on the limit, it really damages you for a few days. "I had to go from 350 metres after that hard day. Im on my knees but all I could do was go. I had to go and not look back after what the guys had done all day. I actually didnt want to go for the sprint today but the guys stayed with me on the climbs. You saw the work they did: the guys ride and ride until their legs wont go anymore, and Im so proud of that." Giacomo Nizzolo was second, with Luka Mezgec third in the 254-kilometre (158-mile) leg from Busseto to Cherasco. Nibali, who finished third and second in his two previous Giro dItalia races, maintained his 41-second lead over Cadel Evans. The mountain stages are coming at the weekend, which is the Australians preferred terrain. After heavy rain throughout the race, the weather improved Friday with the sun shining for most of the trek. T