Geraint Thomas emerged unscathed from a spectacular crash that snapped team-mate Gianni Moscon's bike in two as stage eight of the Tour de France served up another dramatic finale.

As Thomas De Gendt delivered a stunning solo victory in Saint Etienne and Julian Alaphilippe attacked late on with Thibaut Pinot to regain the yellow jersey from Giulio Ciccone, Thomas was grateful his title defence did not suffer the same fate as Moscon's bike.

With a little over 15km of the 200km stage from Macon remaining, the Ineos train was derailed when EF Education First's Michael Woods fell in front of them, leaving riders and bikes scattered across the road.

"I'm fine, but it's just frustrating – obviously it was a key moment in the race," said Thomas, who sported only a minor graze on his arm along with some of the oil from Moscon's chain.

"Woods crashed and just took out Gianni and me. I got tangled in Gianni's bike and took some time to get going."

What was Team Sky always used to boss the Tour's mountain stages from the front of the peloton whether they held yellow or not, but their willingness to follow others was notable on the road to La Planche des Belles Filles on Thursday and almost proved costly on Saturday.

"There was no reason for us to ride so we were in a good position today," Thomas said.

"We were behind Woods and his team – they were the guys riding. It was just unfortunate that he crashed in front of us and took us out but that's the way it goes sometimes."

In the morning, Ineos team principal Sir Dave Brailsford had suggested Thomas was in the form of his life, saying "he's as good, if not better, than he's ever been".

The Welshman needed that form as he got back to the group in just four kilometres and rode his way to 10th place on the day.

"The boys did a great job," Thomas added. "I caught up for the final bit and moved up through the group, but by the time I was in the first 10 or 15 positions that's when they sprinted over the top for the bonus seconds.

"So I was kind of gassed for a bit. It's annoying, and frustrating, but at the same time, to come back like I did shows I had good legs."

Co-leader Egan Bernal was the only Ineos rider not to wait, having avoided the incident and been unaware Thomas had even remained on his own bike.

"I just heard them say 'crash, crash', but he got a bike really fast so I expected him to come (back)," the 22-year-old Colombian said.

"I was ready if I needed to wait for him but they didn't ask me so I just stayed in the group."

It could have been much worse for Thomas as Alaphilippe and Pinot used that final climb as their launch pad, the French duo combining forces as their interests aligned.

Though they could not catch De Gendt, third place on the day was enough for Alaphilippe to regain the yellow jersey he wore for three stages after his victory in Epernay on Monday.

Now the Frenchman will have the honour of sporting it for Sunday's Bastille Day stage to Brioude.

"It was the ideal scenario but I wasn't sure if it could happen this way," the Deceuninck-Quick Step rider said. "I had nothing to lose. I knew my deficit on GC was only six seconds but it was a big task at the same time.

"I couldn't dream of anything better than riding in the yellow jersey on Bastille Day."

While Alaphilippe continues to thrill the French crowds with explosive riding, their general classification hopes are firmly pinned to Pinot, who with bonuses picked up 28 seconds on his rivals to become the best-placed of the main contenders.

The Groupama-FDJ man is now third, 53 seconds down on Alaphilippe and 19 seconds ahead of Thomas in fifth.

But stage success belonged to breakaway specialist De Gendt, who delivered his second career Tour stage win in some style.

Part of a four-man break that attacked from the off, De Gendt moved clear with CCC's Alessandro De Marchi on the Croix de Part, then went solo with 14km to go and held off Alaphilippe and Pinot.

"It hurts so much but it's wonderful," the Belgian said "It's also mission accomplished for the team. Our goal was to come to the Tour to win a stage.

"We almost got it yesterday with Caleb [Ewan]. I've had very good feeling already for the whole Tour and I had amazing legs today."