Lars Boom wins stage five of Tour de France as Vincenzo Nibali retains yellow

This was a stage for the ages, but its images are already seared into memories. The peloton, splattered and scattered by the rain and cobbles along the road to Arenberg Porte du Hainaut. The Dutch rider Lars Boom, his face camouflaged by mud, raising his hands in grim triumph. Vincenzo Nibali, surprising us all with his nimbleness and daring, taking swingeing chunks out his main general classification rivals.

And then the crashes, of which there were far too many to keep count – although the official Tour de France medical bulletin listed 12 riders who needed treatment. Among them was Jurgen van den Broeck, a top 10 contender, who flipped over his handlebars as he was dunked into a ditch.

Afterwards Garmin-Sharp team manager Jonathan Vaughters described it as "absolute war". And there was one major casualty: Britain's Chris Froome, the 2013 champion, who trudged despairingly into the Team Sky car with just over 70km of stage five remaining.

Froome had started the day with his left knee bandaged and his left wrist supported by a lightweight splint, the painful legacy of a crash on Tuesday. But two further spills further weakened his body and crushed his spirit. Later he reached for a familiar adjective – "devastated". But his team-mate Geraint Thomas, who rode so boldly to steer his new team leader Richie Porte into seventh, admitted he had feared the worst when Froome went down after 33km.

“When Froomey crashed early on, it was like: ‘not again’,” he said. “He was just behind me and I thought: that sounds nasty. But he is always positive and he was saying: ‘I will keep going and be fine on the cobbles,’ but then he went down again and it was too much to take.”

Dire weather

On a stage with the cobbles of Paris-Roubaix at its fulcrum, the weather seemed to have reset itself to April. The rain, which began not long after dawn, rarely stopped its beat. Soon tarmac was flooded and cobbles were as skiddy and tricky as black ice. Often the riders aquaplaned past the sparse crowds in a haze.

Due to the bad weather, two of the nine cobbled sectors were removed before the start. That meant there were 13 kilometres of cobbles, not 15.4km. It mattered little. Long before the first cobbles there were crashes. Sebestien Minard skidded near a roundabout and lost his bike. Marcel Kittel did the same round a corner.

Later the peloton split as it swept around a giant roundabout and there were crashes on both sides of the road, including two GC contenders Alessandro Valverde and Teejay van Garderen. But it was Froome who had suffered most and, after speaking to medics, decided he could not continue.

Thrilling race

The Spanish rider Joaquim Rodriguez reckons riding on the cobbles is like giving Rafael Nadal a ping-pong bat not a tennis racket. Van den Brock and

Andrew Talansky

, who were among the unseated, might agree. But it made for thrilling racing. Halfway through the cobbles

Alberto Contador

, who ended up losing two minutes 35 seconds on the stage, was dropped by Nibali. But there was carnage everywhere.

With 15km remaining there were just over a dozen men out in front including Nibali, Peter Sagan and Fabian Cancellara. But on the last stretch of cobbles, Boom escaped to record a famous victory. Nibali retains the yellow jersey by two seconds from his Astana team-mate Jakob Fuglsang.

Meanwhile Thomas and Porte were also happy after escaping Contador and putting Team Sky in a position to challenge in the mountains. “I saw Contador was struggling so I said: Richie, get on my wheel and we will just smash it and see what happens,” said Thomas. Guardian Service