Tony Martin was forced to pull out of the Tour de France after crashing in bizarre circumstances just inside the closing kilometre of stage six. While his Etixx-Quick Step team-mate, Zdenek Stybar, was powering to victory in Le Havre, Martin appeared to veer violently right, barging into another rider who in turn took out Vincenzo Nibali and Nairo Quintana in a domino effect. Martin later said he had clipped the wheel of a rider in front of him. “He abandons,” a spokesman said.

Later it emerged that Martin will undergo surgery in Hamburg on Friday. “The collarbone is in lots of pieces, so it was a major impact,” said Helge Riepenhof, the team doctor. “One of the pieces came through the skin, which means it’s an open fracture. Therefore, even if it was Tony’s wish to start tomorrow, I have to say he is not allowed to.

“He needs surgery straight away, and that is why we are going to the hospital now. We will fix the collarbone there. He is already on antibiotics. It’s a serious injury, and that is why we can’t risk anything and why he cannot be at the start tomorrow.”

Accelerating past on the outside, Chris Froome was lucky to avoid hitting the deck, too. The Sky team leader was sent into a speed-wobble but remained upright and eventually crossed the line unscathed but with a buckled wheel. Nibali initially blamed Froome for the crash and claimed to be “very angry”, but the Sky rider later visited the Astana team bus to have it out with his rival, who apologised upon seeing footage of the incident.

“Did we clear it all up?” said Nibali. “Yeah. We are not footballers, we are cyclists.” In Martin’s absence, Froome takes over as race leader as the next-best-placed rider on general classification. Martin is the second race leader to withdraw through injury, following Fabian Cancellara’s abandonment on Monday.

Tour de France 2015: stage six – as it happened Read more

As the various riders involved in the crash extricated themselves from the pile-up, it quickly became apparent the maillot jaune had come off worst. Riding home one-handed, he was flanked by several team-mates, with Julian Vermote and Michal Kwiatkowski pushing him over the line. “I was extremely unlucky,” said Martin. “I can’t really remember what happened. I touched the wheel of the rider ahead of me. It’s the Tour, luck and bad luck are very close together. It’s often the way accidents happen. You’re not going that fast and then you fall over each other with all your weight.”

With its short, steep climb to a finishing straight that levels out for the final 400m, this stage to Le Havre prompted considerable debate over who would prevail: sprinters or puncheurs, specialists on this terrain. Such sharp ascents can prove tricky for out-and-out fast men such as André Greipel and Mark Cavendish, but are relished by the likes of Peter Sagan, the Tinkoff-Saxo rider whose quick acceleration up small climbs made him odds-on favourite for the win. Sadly, for the fourth time in five stages he finished second or third, this time behind the former cyclo-cross star Stybar, who made an impressive contribution to an increasingly weird week for Etixx-Quick Step.

In just six stages, the Belgian team have had the mother of all internecine bust-ups and been publicly flamed by their owner. They have won two stages and narrowly missed out on two others. They have had a sporting director suspended for a stage after film of him celebrating in a team car showed he was not wearing a seatbelt. And now, having finally got Martin into the yellow jersey for the first time in his career after two near misses, the keystone Quick Steppers have lost it sooner than expected.

Before their incident-packed finish, the peloton had a little under 191 uneventful kilometres with which to contend, setting off from Abbeville in the Somme, heading to Dieppe and then making their way along the north-west coast to the port of Le Havre. On a route that proved the source of many aerial views of topaz seas lapping up against gleaming white cliff faces, the 188 remaining competitors were spared the downpours and violent buffeting feared by many and instead rode in glorious sunshine.

Cruising along after a three-man breakaway that at one point opened a gap of over five minutes, the early excitement within the peloton came in the form of a puncture for Martin and a minor crash for the Movistar rider Alejandro Valverde, who slipped on gravel following a post-pee wheelspin. So far, so quiet.

Following the abandonment of their star sprinter, Nacer Bouhanni, on Wednesday, it was no surprise to see Cofidis revert to their old habit of justifying their otherwise futile existence by committing Kenneth van Bilsen to the escape party, where he was accompanied by Daniel Teklehaimanot and Perrig Quéméneur.

Teklehaimanot realised a lifelong ambition by securing the polka dot jersey, becoming the first black African in race history to wear it, while Bilsen’s late doomed solo effort ended inevitably with 3km to go. He was swallowed by the bunch before Stybar surged clear to take the win on a day of mixed fortunes for his team.

Etixx-Quickstep are not the only team being put through the wringer and have at least enjoyed plenty of success to go with their assorted misfortunes. Orica-GreenEdge, the team of the British twins Adam and Simon Yates, have already lost three riders to broken bones while their Tour debutant, Michael Matthews, struggles on despite two fractured ribs. The Australian team would have been fancied to win Sunday’s team time-trial from Vannes to Plumelec but in a discipline where the clock stops when the fifth rider crosses the finish line, they will do well to get five men down the starting ramp. “The team time trial was one of our goals,” mused one member of their backroom team. “Now with six riders, it’ll be a rest day before the rest day.”

Stage seven takes the peloton from Livarot, hosting the Tour for the first time and known for the pungency of its Graindorge cheese, to Fougères along a long and flat route that Etixx-Quick Step have earmarked as a final chance for Mark Cavendish to open his account before the race enters the mountains. In what has been a preposterously topsy-turvy week for them, absolutely anything could happen.