L'ALPE D'HUEZ, France - Tour de France leader Chris Froome is so dominant that even when he loses time for eating an energy bar, he extends his lead.
The British rider was hit by a 20-second penalty for taking an energy bar from a teammate near the end of the 18th stage Thursday.
But he still increased his advantage over main rival Alberto Contador to more than 5 minutes.
Christophe Riblon became the first Frenchman to win a stage this year, while Froome edged closer to becoming the second British rider to win the Tour after Sky teammate Bradley Wiggins last year.
Contador tried to gain some time back, attacking aggressively on a downhill, but in the end Froome did it for him when he grabbed an energy bar from teammate Richie Porte with about 2 miles to go.
"I was really going into a little bit of a sugar low then," Froome said. "I don't know if it helped me."
Riders are forbidden to take food within 3 miles of the stage end.
"That's one of those things that come with the race," said Froome, whose teammate also got a 20-second penalty.
The 107-mile route from Gap to L'Alpe d'Huez featured two HC ascents of L'Alpe d'Huez - meaning they were so tough they were beyond classification, known as Hors Categorie.
Riblon caught American Tejay van Garderen with about a mile left, on the second ascent.
Riblon threw his hands up and pumped his fists after clinching the second Tour stage win of his career, three years after winning another mountain trek.
Van Garderen finished 59 seconds behind in second, and Italian Moreno Moser was 1:27 behind in third.
Froome finished the stage 3:18 back in seventh, rolling in alongside Porte and nearly one minute ahead of the 11th-placed Contador.
In this final week, there has been feverish media speculation about Froome's dominance, prompting heated debate on social media, cycling blogs and mainstream media.
It prompted his Sky team to give assurances that he is racing clean.
"I can't understand why the yellow jersey is being put on trial," said Riblon, who was part of a nine-man breakaway that surged ahead early on.
On Thursday, Froome's Sky team released his performance data from six races, including this Tour, to a French newspaper in an effort to dispel suspicions of doping.
"It's crazy hearing people talk like this. Of course I'm human," Froome said. "I know what I'm doing is right and I'm extremely proud of what I've done to get here.
"No one can take that away from me."
• What: Stage 19
• When: 3 a.m.
• TV: NBCS