Dutchman Pieter Weening claimed the overall lead after a solo victory on stage five of the 2011 Giro D'Italia on Wednesday but the race was marred again by crashes with teammate Tom Jelte Slagter sustaining a fractured jaw.

With Belgian rider Wouter Weylandt's death in a crash on Monday still hanging over the peloton, Dutchman Slagter fell heavily shortly after one stretch of untarmacked road.

Rabobank team sources said he had fractured his jaw but a hospital scan had ruled out any brain damage.

Overnight leader David Millar also crashed after colliding with stage 3 winner Spaniard Angel Vicioso 50 kilometers from the finish in an intermediate sprint. Vicioso won stage 3 ahead of Millar.

His Team Garmin-Cervelo kit blackened with road dirt, the Scot powered through the massive dustclouds on the off-road sections to regain contact with the main pack.

However, he was dropped on the neverending rise to the Orvieto's hilltop town, finishing 49th, 2 minutes 50 seconds down.

Weening became the first Dutch rider to lead the Giro since 1999 after crossing the line around eight seconds ahead of a 20-strong chase group led by Colombians Fabio Duarte and Jose Serpa and containing all of the major favourites.

With a win in the Vosges mountains in the 2005 Tour de France his last big victory, Weening said the dusty off-road gravel sections of the 191-km stage had been tough going.

"I always knew that the best defence is an attack when it's so dusty because further back you can't see anything," Weening told reporters.

"I wasn't at all sure of my strength on the final climb, so I went for it alone."

Asked if he thought the off-road sections were excessively dangerous, Weening said "I can't complain, because I won.

"Dirt roads are always risky though, and when we saw the race route, we knew it would be tough."

The 2011 Giro d'Italia finishes on May 29 in Milan.

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