Richie Porte is treated by medical staff after crashing during Stage 9 of the Tour de France.  Getty Images

Big crashes shook up the 2017 Tour de France in arguably its toughest stage on Sunday, with overall leader Chris Froome extending his lead while his top teammate and one of his top rivals crashed out. Stage 9 of 21 featured punishing climbs and hair-raising descents in eastern France's Jura mountains where riders exceeded speeds of 45 miles per hour. Froome getting to the finish marked a crucial step in the three-time champ's shot at a fourth tile, but Richie Porte, a top challenger who been fifth overall, never made it there after a gnarly high-speed crash on the stage's final descent.

Porte missed a left-hand bend, cartwheeled across the road and bowled over another rider, Dan Martin, before slamming into a stony, vine-covered bank. The Australian was first treated by medics as he lay on the tarmac and then taken away in an ambulance to the hospital for checks.

Fabio Baldato, one of the directors of Porte's BMC team, said the rider had shoulder pain but "was always conscious. He knew what happened and was asking for his helmet and his glasses."

Also seeing his 2017 Tour end abruptly was Froome's teammate Geraint Thomas, who had held the overall lead for the first four days of the Tour. Their Sky team said Thomas broke his collarbone. For Froome, the crashes took some of the shine off what otherwise was a sterling day for him, because some dangerous rivals lost valuable time, most notably two-time Tour winner Alberto Contador and, to a lesser extent, Colombian Nairo Quintana -- a three-time podium finisher at previous Tours.

"That was horrific," Froome said of Porte's crash. They used to be teammates at Sky before Porte left for BMC.

Froome placed third in the stage, narrowly beaten in a final sprint by Colombian Rigoberto Uran at the finish in Chambery, in the Alps. French rider Warren Barguil was just millimeters behind in second place -- so close that he burst into tears thinking he had won, only to discover moments later that he hadn't.

Uran thought Barguil had beaten him to the line. It was a moment of confusion aptly fitting for a day of racing so chaotic that it was difficult at times to keep track of all the drama, as riders scattered like leaves over the 181.5-kilometer (112-mile) stage -- struggling at their own pace on its brutal succession of climbs.

"They told me I had won but I was convinced Warren had won it," Uran said.

For his third place, Froome was awarded four bonus seconds that allowed him to consolidate his overall lead. With Thomas, who had been in second place, now out, Italian Fabio Aru climbed to the second spot in the race rankings -- 18 seconds behind Froome overall. French rider Romain Bardet, runner-up to Froome last year, is third overall, 51 seconds behind Froome.

With awful timing, Froome survived a breakdown of his bike gears on the last, hugely tough climb that forced him to change machines just when he was riding furiously in a bunch with other top contenders.

As Froome was frantically signaling to members of his team following in a car that he was in trouble, Aru choose that exact moment to accelerate away, followed by other top challengers, including Quintana and Porte.

For a few moments, Froome's Tour seemed to be hanging by a thread.

But Aru and the others then slowed rather than press home their advantage -- apparently adhering to the Tour's unwritten rule that challengers shouldn't attack the race leader when he's in difficulty not of his own making.

With a replacement bike and teammates who waited for him, Froome ground his way back into the pack. Higher up the climb, he appeared to swerve across the road and nudge Aru with his right shoulder.

But the Briton said that was purely accidental, "a bit of a wobble," not an attempt to reprimand the Italian for his earlier attack.

"It was in no way a swipe at Aru," Froome said.

"I want to say `thank you' to the other riders for not attacking," Froome said. "They waited until I had changed bikes. That's sporting and pleasing to see."

Aru was riding right behind Froome when the Tour leader raised his hand to show that he was in trouble. Still, the Italian insisted that he hadn't seen Froome's hand signal, and that it had always been his intention to attack at that spot on the climb, with about six kilometers (4 miles) left to ascend on the Mont du Chat.

"Then I heard on the radio that Froome had stopped," Aru said. "When I heard it on the radio then I stopped."

Of the day's seven notable ascents, three had the toughest "hors categorie" (beyond classification) rating on cycling's sliding scale of climbing difficulty. Not since 2011 had organizers shoehorned three such climbs into the same stage. The total elevation Sunday, when all the ascents were added together, was 4,600 meters (15,000 feet), more than half the height of Everest. It did lots of damage. Several riders rolled in behind the leaders with torn jerseys and shorts, bloodied and sporting bandages -- victims of multiple crashes.

Contador, who couldn't cope with the uphill pace on the last climb and poured water over his head and neck to try to cool down, rode into Chambery more than four minutes after Froome -- effectively dashing his hopes of victory in Paris on July 23. Quintana also got left behind but did a better job of limiting the damage -- finishing 75 seconds behind Froome.

Information from The Associated Press was used in this report.