Tour de France 2017: Marcel Kittel wins sprint finish with Mark Cavendish fourth

Defending champion Chris Froome crashed in the wet conditions, 30km from the finish, but finished without losing any of the advantage he gained over his rivals on stage one.

Mark Cavendish was "happy" to finish fourth after a bout of glandular fever.

Thomas, who also crashed, leads Swiss rider Stefan Kung by five seconds.

The Welshman, who won the opening time trial on Saturday and finished in the peloton on Sunday, said: "We were all in a decent position, but a few guys came past us pretty quickly and slid and we all just went down.

"We got up pretty quickly though. Anything can happen and I wouldn't take anything for granted. Tomorrow is another day and we will be doing all we can for Froome."

Three-time champion Froome was one of a number involved in the crash as the peloton came off a roundabout during the 203.5km ride from Dusseldorf to Liege, Belgium.

He was paced by former world champion and Team Sky team-mate Michal Kwiatkowski back to the peloton but then immediately raised his hand, indicating to his team car that was something wrong.

He lost more time changing his bike but Kwiatkowski again waited to help Froome catch up.

When asked if he had injured himself, Froome replied: "No. I just lost a little bit of skin from my backside.

"That's the nature of the race. We know in slippery conditions like that, every time the race comes on there's a big risk something could happen and today there was just a touch of wheels, or someone slid just a few wheels ahead of me, and at those speeds you just can't avoid it.

"I think a few of us went down but thankfully everybody's OK and got to the finish all right without losing any time to our rivals, so that's the main thing."

Froome remains sixth, 12 second behind Thomas, but crucially 35 seconds ahead of Richie Porte and 36 clear of Nairo Quintana, two of his main rivals for the overall win.

Cavendish content with fourth

Cavendish gave an honest assessment of his first big sprint at the Tour after missing two months of the season with glandular fever and only returning to competitive racing at the Tour of Slovenia in June.

"It's as I expected, I'm happy with that," he said. "Six weeks training and fourth on a stage of the Tour. You always want to win but fourth on a Tour stage is a lot better than I expected.

"I was on the ideal wheel in the end but when Kittel went I was sprinting in his wheel and there was no way I could go past him.

"I didn't feel like I had power in my legs. I got where I was by jumping on other wheels to get up."

Kittel in tears after win

The German, who edged out French champion Arnaud Demare and countryman Andre Greipel to win, immediately broke down in tears.

"I'm super happy I got this victory," he said. "It was an incredible start in Germany and it would be wrong to say I had no expectation or pressure. I wanted this win and it was a big goal to start in Germany and win the stage."

A 10-second time bonus for winning the stage lifted Kittel to third in the overall standings, six seconds behind Thomas.

Monday's third stage from Verviers to Longwy is 212.5km as the race enters France for the first time this year and finishes with an uphill drag that should rule out the sprinters and could see Thomas retain the race lead.