The Giro d'Italia lived up to its reputation as an unpredictable race today when German John Degenkolb snatched victory in stage five after most of the bunch was held up behind a late crash in a chaotic finale.

Degenkolb was one of only a few riders to escape trouble in the last corner after his Argos-Shimano team mate Luka Mezgec went down on a slippery road, and launched a lung-burning 800-metre sprint to catch a lone rider up front.

Spain's Angel Vicioso was second and German Paul Martens finished third, while Italian Luca Paolini retained the overall leader's pink jersey.

Pre-race favourite Bradley Wiggins was held up behind the crash caused by slippery roads but because the incident occurred in the last three km of the 203-km stage, was credited back the time he lost and stayed sixth overall in an unchanged top 10.

Paolini still leads Wiggins's team mate Rigoberto Uran of Colombia by 17 seconds with Italian Vincenzo Nibali and defending champion Ryder Hesjedal of Canada fourth and fifth, 31 and 34 seconds off the pace respectively.

Tour de France champion Wiggins also lies 34 seconds behind Paolini.

International Cycling Union (UCI) regulations state that a rider who is held up by a crash in the final three km - with the exception of uphill finishes - is credited with the same time as the main bunch.

On Tuesday, Wiggins lost 17 seconds after the UCI commissaire stated that the 'three-km rule' could not be applied to the Briton because the peloton had already split when a crash occurred.

All the favourites stayed safely in the bunch during Wednesday's stage but as torrential rains washed out the streets of Matera, forming rivers, chaos was expected and arrived.

Slovenian Mezgec crashed in the final corner and was left in apparent agony on the side of the road with most of the peloton being held behind, some of them having to dismount their bikes.

Team Argos-Shimano said Mezgec was fine.

Degenkolb was vigilant, and a tad lucky as he managed to sneak through.

"We said it was going to be our D-day so there was actually a lot of pressure on me," Degenkolb told reporters. "We chased down the breakaway riders, took our responsibilities."

The 24-year-old sprinter delivered, rewarding his team mates for their efforts.

"I like to be under pressure," he said. "It was pretty special today, I was very lucky in the end that I did not crash."

Briton Mark Cavendish, who struggled in the category-four climb some 25km from the finish and could not contest the sprint, is expected to be back in business on Thursday's sixth stage, a 169-km flat ride between Mola Di Bari and Margherita Di Davoia.