LILLE, France -- Back on the race's home turf after three days in England, the Tour de France faces a first possible shakeout Wednesday over the bone-rattling cobblestones in northern France.
Many riders dreaded the forecast for rain, meaning the stones will be slick.
Defending champion Chris Froome scuffed his left knee and elbow and injured his wrist Tuesday during Stage 4, a crash that couldn't have come at a worse time for him.
"Took quite a tumble today but I'll definitely be starting tomorrow with no serious damage," Froome said on Twitter: "It'll be a tough one for everyone on the cobbles!"
Astana team leader Vincenzo Nibali of Italy kept the yellow jersey in what he called a "crazy race" -- a 101-mile ride along the Belgian border. Froome and two-time champ Alberto Contador are among 20 riders trailing Nibali by two seconds.
Marcel Kittel got his third stage victory in this Tour and the seventh of his Tour career on Tuesday. Unlike his wins in Stages 1 and 3, when he made victory look easy, Kittel won by a half-wheel length at the end of the ride from Le Touquet-Paris Plage to Lille Metropole.
Kittel, of the Giant-Shimano team, didn't celebrate this time, but panted. The gesture at the line came from runner-up Alexander Kristoff of Norway, who swatted the air in frustration after being beaten by the barreling German.
After a difficult day of crosswinds, pockets of rain-smattered roads, and jumpy nerves in the peloton, Kittel said: "It's never easy ... (I was) lucky just enough at the finish line."
Race doctor Florence Pommerie said Froome's injuries amounted to "essentially a few scratches."
In the sixth stage of the Criterium du Dauphine race last month, Froome took a spill during a descent and banged up a hip, shoulder and elbow. The next day, he lost the race's yellow jersey to Contador.
An aching wrist could mean pain ahead for Froome. The cobbles on today's run from Ypres, Belgium, to Arenberg Port du Hainaut, could make it difficult for him to keep his hands on the handlebars. It includes stretches of bumpy road familiar to riders of the famed Paris-Roubaix one-day classic.
"It's going to be a crazy stage for everyone," said Philippe Mauduit, a director for Contador's Tinkoff-Saxo Bank team. "We'll do whatever we can to stay near the front to avoid getting involved in crashes or held up by any pileups but that's what everybody wants and therefore the pace will be extremely high."
Before the fourth stage, 2010 winner Andy Schleck of Luxembourg dropped out because of an injury. On Sunday, British sprinter Mark Cavendish quit after crashing in Stage 1.