Alexis Vuillermoz gave the hosts their first victory at the Tour de France this year with success on the eighth stage on Saturday.
The 27-year-old former mountain biker took his chance with 800m left on the tough finish at the Mur de Bretagne to take a solo victory.
Ireland’s Dan Martin timed his counter-attack a shade too late and finished second at 5sec, frustrated at having reacted too late to Vuillermoz’s initial punch.
A shredded peloton arrived next at 10sec with Spaniard Alejandro Valverde winning the sprint ahead of Frenchman Peter Sagan of Slovakia and Frenchman Tony Gallopin.
Chris Froome finished eighth in the same group to maintain his overall lead by 11sec from Sagan, while American Tejay Van Garderen is third at 13sec.
But Briton Froome, the 2013 winner, did strike another blow to reigning champion Vincenzo Nibali who lost 10 seconds as he was dropped by the lead group on the 2km climb to the finish with its 6.9 percent gradient.
He is now 13th overall at 1min 48sec.
Froome admitted it was a shock to hear Nibali had struggled.
“I was very surprised to hear that actually, especially given that up the final climb it was predominately into a headwind up there, which made it relatively easy to stay on the wheels,” he said.
“So I’m really surprised to hear that, especially with a relatively big group up front.”
Two-time former winner Alberto Contador and Colombian Nairo Quintana stayed with the lead group, though, finishing 14th and 17th respectively to remain at 36sec and 1min 56sec of Froome.
Following Sunday’s team time-trial and Monday’s rest day, the true battle will commence on Tuesday’s first mountain-top finish at La Pierre-Saint Martin with a final 15.3km, 7.4 percent climb to the summit.
Vuillermoz’s victory went some way to glossing over what had been a disappointing Tour for the hosts so far.
Not only did they have to wait eight stages for a winner but overall hopes Thibaut Pinot and Romain Bardet had already lost 6min 18sec and 2min 54sec respectively, badly hurting their hopes of a podium finish.
Pinot finished 25sec behind the winner and Bardet, a AG2R teammate of Vuillermoz, was another six seconds behind that.
Earlier, a four man breakaway took off within 5km of the start but were never allowed more than a 3min lead over the pack.
But they were reeled in shortly after the intermediate sprint, 108km into the stage, after which a new three-man break formed, with Pole Bartosz Huzarski managing to get into both.
But that one was never given more than a minute’s leeway and was brought back with 8km left as the favourites’ teams cranked up the pace to set up their leaders for the final battle.
Results from the 8th stage of Tour de France a 181.5km ride from Rennes to Mûr-de-Bretagne on Saturday:
1. Alexis Vuillermoz (FRA/ALM) 4hr 20min 55sec
2. Daniel Martin (IRL/CAN) at 0:05sec
3. Alejandro Valverde (ESP/MOV) 0:10.
4. Peter Sagan (SVK/TIN) 0:10.
5. Tony Gallopin (FRA/LOT) 0:10.
6. Greg Van Avermaet (BEL/BMC) 0:10.
7. Adam Yates (GBR/ORI) 0:10.
8. Chris Froome (GBR/SKY) 0:10.
9. Bauke Mollema (NED/TRE) 0:10.
10. Tejay Van Garderen (USA/BMC) 0:10.
Overall standings after the 8th stage of the Tour de France, a 181.5km ride from Rennes to Mûr-de-Bretagne on Saturday:
1. Chris Froome (GBR/SKY) 31h01min 56sec
2. Peter Sagan (SVK/TIN) at 0:11sec.
3. Tejay Van Garderen (USA/BMC) 0:13.
4. Tony Gallopin (FRA/LOT) 0:26.
5. Greg Van Avermaet (BEL/BMC) 0:28.
6. Rigoberto Uran (COL/ETI) 0:34.
7. Alberto Contador (ESP/TIN) 0:36.
8. Warren Barguil (FRA/GIA) 1:07.
9. Zdenek Stybar (CZE/ETI) 1:15.
10. Bauke Mollema (NED/TRE) 1:32.
– Agence France-Presse