PORRENTRUY, Switzerland — Bradley Wiggins kept the yellow jersey at the Tour de France. Keeping his cool was another matter.
The former Olympic champion, with ambitions to be Britain’s first Tour winner, unleashed a profanity-laced tirade after Sunday’s eighth stage in which the race entered Switzerland.
Thibaut Pinot, at 22 the youngest competitor, was the day’s winner and gave France its first stage victory this year. Wiggins quashed a late attack by defending champion Cadel Evans to hold the lead.
Wiggins’s Team Sky has controlled the Tour in a style reminiscent of Lance Armstrong’s former US Postal team. The Briton, however, lost his composure when asked by a reporter to comment on comparisons between the teams and ‘‘cynics who believe that you have to be doped up to win the Tour.’’
Wiggins, angered by the chatter on social media, let loose with an expletive-filled outburst.
‘‘I cannot be dealing with people like that. It justifies their own bone-idleness because they can’t ever imagine applying themselves to anything in their lives,’’ he said. ‘‘And it’s easy for them to sit under a pseudonym on Twitter and write that.’’
The US Anti-Doping Agency last month filed charges against Armstrong, accusing the seven-time Tour champion of using performance-enhancing drugs. Armstrong denies any wrongdoing.
The Tour is without two-time champion Alberto Contador this year while he serves a doping ban linked to the race in 2010.
Wiggins is looking to move from three-time Olympic track gold-medalist to a rising star of the Tour de France roads.
Sunday’s ride into the Jura range next to the Swiss Alps offered double drama: a hard last climb that splintered the pack, and a tense chase of Pinot to the finish.
Pinot burst from the pack and overtook a breakaway rider during a steep, final climb to win the 98-mile stage from Belfort in eastern France to the Swiss town of Porrentruy.
‘‘I will remember this day my entire life,’’ Pinot said as teammates embraced him. ‘‘I can’t yet get my mind around it.’’
Evans of Australia was second, 26 seconds behind, but didn’t gain any time on Wiggins, who was fourth in a small group that included most of the remaining pre-race favorites.
Wiggins leads Evans by 10 seconds.
Sunday’s race was marred by yet another crash, bringing a high-profile withdrawal. Defending Olympic champion Samuel Sanchez pulled out 35 miles into the stage. He broke his right hand and injured his left shoulder, and could miss the London Games.