MARSEILLE, France — Lance Armstrong kept his overall lead in the Tour de France on a sweltering day despite losing time after being stuck in a pack of riders blocked by street protesters.
Armstrong finished today's 10th stage in a group that completed the 136-mile ride more than 20 minutes behind Denmark's Jakob Piil, a Team CSC rider who won a Tour stage for the first time.
All of Armstrong's key rivals were in the main pack with him, meaning they did not gain time on the Texan, who is trying to tie Miguel Indurain's record of five straight Tour titles.
Armstrong, wearing the leader's yellow jersey, finished in 45th place — 21 minutes, 23 seconds behind Piil — on a day when organizers said temperatures soared to 104 degrees along the route.
"It's definitely the hottest Tour that most of us can remember," Armstrong said. "We've always had hot days but never so many in a row."
Alexandre Vinokourov, a Kazak rider for Team Telekom, remains second overall, 21 seconds behind Armstrong. Spain's Iban Mayo, an Euskaltel-Euskadi rider, is third overall, 62 seconds back. Tyler Hamilton, a U.S. rider and former Armstrong teammate, is fifth overall.
Finishing in the same time as Armstrong today were Vinokourov (53rd place), Mayo (42nd), 1997 winner Jan Ullrich (34th) and Hamilton (36th).
On Wednesday, riders get a rest day, and Armstrong said he probably will take a "big nap." Racing resumes Thursday with a 95.2-mile stage from Narbonne to Toulouse. Friday is a time trial.
"It may be the most important time trial I've ever done in the Tour," Armstrong said.
After three grueling days in the Alps, the main pack appeared happy to take it easy during this stage. The riders let a breakaway group — no threat to the overall leaders — get far ahead.
Piil was among that breakaway group. The nine riders surged ahead just 9.9 miles into the race and stayed that way for more than 124 miles, the longest breakaway so far in this Tour.
Piil beat Italian rider Fabio Sacchi of the Saeco team in a final sprint to the finish at Marseille. Bram de Groot of the Netherlands, with the Rabobank team, was third.
"I've been chasing a stage victory on the Tour for two years now," Piil said. "I finally have it. I'm very happy."
The protest forced riders to stop after supporters of radical farmer Jose Bove ran into the road and blocked cyclists near Pourrieres, about 91 miles into the race.
Tour officials immediately ruled the protest was a "normal race incident," meaning riders would have to suffer the penalties of being caught in the protest. However, Armstrong's main rivals got caught in the pack as well, so his overall lead was not affected. In all, the main pack lost about 90 seconds, organizers said.
A day earlier on Bastille Day, away from the Tour, police arrested six protesters, including three carrying banners in support of Bove. He was jailed last month for destroying genetically modified crops and served about six weeks in jail in 2002 for ransacking a McDonald's restaurant construction site.
Armstrong's performance in this Tour has been fraught with struggle and nerve-racking close calls. He narrowly missed crashing for the second time Monday, and a week ago he avoided serious injury in the opening stage in a pileup.
On Monday, Armstrong skidded off the road as Joseba Beloki jammed his wheel and fell. The Spanish rider, who was in second place overall, broke his right leg, elbow and wrist, doctors said. He was being flown to Vitoria, Spain, for surgery on his right leg, organizers said today.
"I feel very sorry for him," Armstrong said after that stage. "You don't want to lose one of your main competitors through a crash."