Britain's Mark Cavendish won his second successive stage and fourth of the 2013 Giro d'Italia on Friday.

Giacomo Nizzolo of Italy finished second in the bunch sprint that decided the 254-kilometre stage from Busseto to Cherasco, the longest of this year's race. Slovenia's Luka Mezgec was third.

Italy's Vincenzo NIbali remains in the overall lead on a day when 2012 winner Ryder Hesjedal of Canada and pre-race favourite Bradley Wiggins both failed to start the stage because of illness. The pair subsequently withdrew from this year's race. 

Wiggins will now return home to focus on recovery and preparation for the Tour de France, where his failure here could lead to fresh controversy over Team Sky's plans to support team-mate Chris Froome over their defending champion.

For now, however, the 33-year-old was left to lick his wounds after a Giro which never really went according to plan for him.

"I'm disappointed, but some things you can't control," the seven-time Olympic medallist told Sky Italia. "It's really disappointing to stop in this way because we came here for so much more.

"This morning the doctor said: 'That's enough', because I didn't really have much sleep last night and yesterday was really bad and we had a long stage again today.

"I'm disappointed, but some things you can't control"  Bradley Wiggins on his withdrawal from the race

"It's how long you can keep fighting for before you say the GC has gone now."

After clinching his 40th Grand Tour stage win and 101st of his career, Cavendish told reporters he had not expected to take the victory on a course with such a difficult finale.

"Its a bit of a bonus, an extra trophy, I don't know how I'm going to recover before the mountains."