After Bradley Wiggins flirted with disaster on Tuesday, on Wednesday it was Mark Cavendish's turn to see his Tour and Olympic ambitions flashing past in front of him as the front part of the Tour's peloton hit the deck. Wiggins had escaped crashes twice the previous day, once having to run up the verge cyclo-cross style with his bike on his shoulder to avoid a pile-up, and here Cavendish came down heavily in a chute involving at least 20 riders just as the peloton was winding itself up for the sprint on the banks of the Seine.

Cavendish's ambition of winning the Olympic road race on 28 July remains intact, although he was battered and bruised after falling at close on 40mph, but his chances of defending the Tour de France green points jersey he won last year have taken a severe knock. He had begun the day 43 points behind the Slovakian prodigy Peter Sagan, and he lost another 18 after Sagan finished fifth here behind the German André Greipel, who was one of the select group fewer than 30 who avoided the pile-up.

Greipel's Lotto-Belisol team were at the front of the bunch when the crash took place, as the field appeared to ease slightly after plummeting to the banks of the Seine after scooping up a three-rider escape that had led since the start of the stage. As a result, they were able to deliver the German to the line with a perfect lead-out, completed when his last man, Greg Henderson of New Zealand, swung off at 250m to go.

It came close to the front of the field, a dozen riders or so back, on the left-hand side of the road, with the wind from the right pushing the field close to the kerb. The riders exposed to the breeze were attempting to squeeze into the shelter and that was enough to cause a touch of wheels. The pile of bikes and bodies obstructed most of the field, including Wiggins, who was baulked but to no ill effect. Fortunately the race was a few hundred metres inside the 3km to go flag when it happened, meaning that all the riders who were affected were credited with the same time.

Cavendish took several minutes to get back on his bike, and looked to be severely winded by the impact, which left his rainbow jersey cut on the back and shoulders. "He's covered in cuts," said his directeur sportif, Sean Yates. "All over. On his back, on his legs, on his shoulder, on his hip, so yeah, he's beaten up." The Manxman's main sprint domestique, Bernhard Eisel, also fell, and suffered a deep cut to his eyebrow which was stitched up shortly after the finish.

"Both Cav and Bernie had heavy crashes but luckily all their injuries seem relatively superficial and there are no broken bones," said the Team Sky doctor, Alan Farrell. "We are very hopeful in terms of the prognosis and outlook." Both will ride on but neither will be comfortable.

It was Cavendish's fourth crash of the year, after a tumble in the Tour of Qatar at the start of the season and a pair in the Giro d'Italia, which he still managed to finish. It came just after a reminder of his Olympic ambitions with his selection in a five-man Great Britain road race team which includes David Millar as road captain, Bradley Wiggins and Chris Froome – who will also ride the time trial as well – and the newly crowned national champion Ian Stannard. Asked if the team had any other plan than to ensure a sprint for Cavendish, Millar said the Manxman is GB's "Plan A, Plan B and Plan C".

The finale of every flat Tour de France stage leaves nerves on edge, especially in the first week, but according to the yellow jersey wearer, Fabian Cancellara, this year is a little different, with the fight to stay at the front all the more intense because Cavendish's HTC train are no longer there to set the pace. The result is a scrappier race with more riders fighting to get on the right wheel.

"In my opinion there is not one team making a train like [Mario] Cipollini or Cav had in the past," said Cancellara. "The fight is bigger, everyone is fighting to put his rider in the right place. Only Lotto with Greipel are riding. That is probably the difference, there is no sprinter team with six or seven riders putting everything in line. With 3km to go there was a mass of riders and someone touched someone else. It's not done on purpose, just everyone fighting to get the best spot."