South African Daryl Impey won stage nine of the Tour de France on Sunday, leaving local fans to settle for Frenchman Julian Alaphilippe keeping hold of the yellow jersey on Bastille Day.

Impey, wearing his national champion jersey, was part of a mass breakaway that quickly opened a 10-minute gap and extended it throughout the race with the pack eventually trailing in 16 minutes after Impey had beaten Belgian Tiesj Benoot to the line.

Defending champion Geraint Thomas and the other overall title contenders finished together in a low-key finale to the 170km rolling run.

"That was a really tough race. I'm so happy to win on July 14," said a broadly smiling Impey, who crossed the line with both arms aloft, releasing a huge victory cry.

The 2019 Tour Down Under champion and all-rounder won a Tour de France team time-trial in 2013, and a few days later took the overall lead to become his nation's first yellow jersey holder.

"This is my greatest ever victory, just as good as wearing the yellow jersey, nothing can top this," he said. "It was a tough, solid day."

Impey is a teammate of the British Yates twins, with Adam angling for the overall title this year.

"There's no way I was getting involved in a breakaway today, but I expected a select bunch sprint," team leader Adam said.

Bardet And Porte Attack

After a frantic day over seven mountains on Saturday, the stage embarked from Saint-Etienne's football stadium in a festive Bastille Day atmosphere with many fans shouting for local man Romain Bardet as well as Alaphilippe.

Bardet and Australian contender Richie Porte tried a cheeky breakaway on the approach to the town of Brioude, but after brief deliberation Ineos and FDJ upped the tempo and reeled them in, and that was the end of the hostilities.

"Obviously we had to be aware of (Bardet's attack)," Thomas said after the race.

"He's quite far down on GC (3min 20sec) but Bennett and Richie Porte were there. All three of them you don't want to give them any time back if you don't have to," the Welshman added.

Yellow jersey wearer Alaphilippe was also relieved.

"This is a day I'll never forget," said the overall leader.

"All those people shouting my name, it really is something, and my grandfather was there at the finish line, so it was really special," added the former soldier, who came into the race without any aspirations of becoming France's first Tour winner since 1985.

"The toughest is still to come, even if it's been hard so far.

"I'm not dreaming of a Tour win, I'm dreaming of keeping the yellow jersey as long as I can.

"I think I can limit the damage on the (stage 13) time-trial. Not win, but hold my own."

"But if it turns into a mass brawl between the big guys on the Tourmalet I think I might really suffer," he said of the fearsome Pyreneean mountain scheduled for stage 14 and its lunar landscape.

The race finished in Bardet's hometown of Brioude, where the title of the local newspaper, 'La Montagne', aptly describes the surrounding region's terrain.

"I had tears in my eyes at the end," said the 28-year-old Bardet.

"This is where I first rode a bike, freely as a kid, things have changed a lot," said Bardet.

Some 7,000 other locals and the great number of visitors were getting ready to celebrate on Sunday with a Boney M tribute band, while Michelin Guide three-star tourist attraction, the Basilique Saint-Julien, was plastered with a massive image of Bardet on its walls for the occasion.