Richie Porte powered into fifth overall and Chris Froome claimed the yellow jersey as the new race leader after the first mountain finish of the Tour de France let the true contenders shine.

Italian Fabio Aru of Astana won the stage after attacking two kilometres from the summit finish, but it was third-placed Froome and fourth-placed Porte who were the big winners.

Froome and Porte tested each other, playing a game of cat and mouse on the final climb before finishing third and fourth respectively.

By finishing third Froome took the yellow leaders jersey off teammate Geraint Thomas, who struggled on the final climb and is now 12 seconds behind Froome.

Ireland’s Daniel Martin finished 16 seconds behind Aru after riding away from Froome and Porte.

Chris Froome, right, and Australia’s Richie Porte grimace in the last meters of the fifth stage of the Tour de France on July 5, 2017. Photo: AP

Porte’s Team BMC had been at the front of the peloton for much of the race as they chased down the breakaway but on the final climb the Australian — who is looking to emulate Cadel Evans’s 2011 le Tour win — was left alone.

Porte though defended his teammates and said they were not burnt out helping him to the front as he chased the stage.

“To sum it up it was fun today,” Porte said.

“We really took the race up to Sky, who didn’t really want to go for the stage and it worked out for us.

“All in all it shows the team is super strong.”

And while Team BMC might just be ‘super strong’ Aru was the one with all the power in his legs as he delivered a bike-shaking sprint up the final climb to move into third in the overall classification, 14 seconds behind Froome.

After that climb Porte believes Aru is a real general classification threat.

“Aru is flying at the moment,” Porte added.

“He is one of the guys to watch for sure. The way he jumped away there when Sky tried to chase… I tip my hat to him but now he has to take a little bit more pressure.”

Aru said he took his inspiration for the stage win from the man who prevailed there in 2014, Vincenzo Nibali.

“I had seen a video of Nibali’s win and I tried to do the same to see what would happen,” said the 27-year-old Aru.

“I wanted to test my rivals, I did not have the stage win in mind but obviously it’s a great day.”

Romain Bardet, France’s great hope for a home win, was fifth, just ahead of Britain’s Simon Yates and former Team Sky man Rigoberto Uran and two-time Tour winner Alberto Contador.

The Tour returns on Thursday with another long flat stage of 216 kilometres between Vesoul and Troyes.

– with AAP