LILLE, France (AP) -- 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 163.5-kilometer (101-mile) ride along the Belgian border. Froome and two-time champ Alberto Contador are among 20 riders trailing Nibali by two seconds.
KITTEL MAKES IT THREE
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. French rider Arnaud Demare was third.
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.''
THE CHAMP CRASHES
Minutes into the stage, Team Sky leader Froome went tumbling after one rider bumped another - like a succession of dominoes - who crossed the Briton's front wheel. He skinned his left knee, left elbow and hurt his left wrist, but got back on his bike. Clinging to the race doctor's car, he got bandaged and rejoined the pack. Then a teammate dropped back to get a splint at Sky's car, and pedaled it up to the ailing Froome.
Race doctor Florence Pommerie told French TV his injuries amounted to ''essentially a few scratches.''
Nibali, said his team informed him through his earpiece about Froome's mishap, and went back to see whether he was OK. Froome responded, ''more or less,'' according to the Italian. The Sky leader went straight into the team bus and didn't speak to reporters after the stage.
Dave Brailsford, the Sky team boss, said Froome described feeling good at the end. Froome was undergoing X-rays after the stage, but the team didn't immediately comment on the results.
LOSE ENERGY AGAIN?
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 - citing stiffness in his thighs and a loss of energy from the crash.
An aching wrist could mean pain ahead for Froome. The cobbles on Wednesday's 155.5-kilometers (97-miles) 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 tomorrow,'' said Philippe Mauduit, a sports 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.''
Said Nibali: ''Tomorrow, we just have to make it through the day. ... Let's hope it's not raining.''
Before the fourth stage, 2010 winner Andy Schleck of Luxembourg dropped out because of an injury in a crash a day earlier. On Sunday, British sprinter Mark Cavendish quit the race after crashing in the final sprint in Stage 1 and damaging his right shoulder.
Kittel has already acknowledged that his job is easier without Cavendish in the race. The Giant-Shimano rider is not a threat for the yellow jersey: Kittel is not a good climber and lost nearly 20 minutes to Nibali in an up-and-down Stage 2.
Europcar rider Thomas Voeckler and Luis Mate, a Spaniard with Cofidis, jumped from the pack early in the stage, setting the pace. First Mate fell back and the Frenchman was overtaken by the pack with about 17 kilometers (10 miles) left.
Associated Press writer Greg Keller in Lille contributed to this report.