Britain's Steve Cummings won stage seven of the Tour de France as an impressive solo ride on the final climb saw him win by more than a minute.
Cummings' success means four of the first seven stages of this year's Tour have been won by British riders, with Mark Cavendish victorious in three.
BMC's Belgian rider Greg van Avermaet was fifth to extend his overall lead.
Team Sky's Chris Froome finished safely despite an inflatable arch, marking 1km to go, collapsing onto the road.
British rider Adam Yates, of Orica-BikeExchange, was sent flying as the obstacle deflated in front of him after opening a small gap on the peloton.
It was initially unclear whether that advantage would count as Yates, who has impressed already on this Tour, was classed as having lost three minutes and 38 seconds on other general classification riders after being patched up for injuries.
But organisers revised the result to include his seven-second advantage held at the 3km mark, meaning the 23-year-old is now second in the overall standings, five minutes 50 seconds behind Van Avermaet.
Cummings win marks day of high drama
Englishman Cummings, 35, was part of a 29-strong breakaway group that established a lead early in the 162.5km stage - the first in the Pyrenees - and was one of four riders who remained clear with 35km to go.
With 25km left, he broke free from that group and never looked back as he increased his lead up the first category one climb of this year's Tour, the Col d'Aspin.
That also put him clear of Giro d'Italia winner Vincenzo Nibali, who tired towards the end and finished fourth, although the Italian did claw back some time on those ahead of him in the general classification.
Once Cummings, who claimed his first Tour stage win last year for South Africa-based MTN-Qhuebeka on Nelson Mandela Day, reached the top he was far enough clear to negotiate the descent into the finish in Lac de Payolle.
His 65-second advantage over Daryl Impey in second gave Team Dimension Data - for whom Cavendish also rides - their fourth stage win of the race.
"I feel pretty exhausted, but I'm obviously ecstatic," he told ITV4. "The team has been fantastic. It's great to be with Mark Cavendish - he's such a legend - and today was a brilliant day.
"It was hot at the end. I was cooking up a bit, but I gave it everything to the top of Col d'Aspin, knowing the race had finished by the time I got there."
Should Cummings be part of the British Olympic team?
Cummings' victory at last year's Tour also came courtesy of a breakaway, and he has also won three world tour stages this year.
That has led to calls for him to join the British team for this summer's Rio Olympics, though that would be a significant and late change of heart by selectors.
Asked if he should be picked for the Olympics, which start on 5 August, Cummings said: "I don't know. If I was coach I would, but I'm not a selector. They have experts there so let them get on with it."
BBC Radio 5 live commentator Rob Hatch added: "On form he merits selection, however British Cycling clearly have a plan to ride for Froome.
"Cummings would be a strong outsider to take the win in Rio, but questions have been raised about how committed he would be riding for Froome. The Olympic teams are small - just five riders - and Britain obviously feel they can't afford the luxury of taking a rider as a Plan B.
"I don't believe there's any way back for him."
What does it mean for the general classification?
The drop into the finish after a long climb played into the hands of Nibali, who is an accomplished descender and was looking to make up time after a poor start to his Tour.
The Astana rider began the day with a gap of over 14 minutes to leader Van Avermaet, but his efforts in the breakaway group brought him 50 seconds closer to his rivals for the general classification despite previously insisting his overall challenge was over.
The fact it was not more was down to a late charge from the peloton, of which Froome was a part, as they realised Nibali had the potential to do more damage. At one point he was over four minutes in front.
Van Avermaet was one of the surprises of the day, as he hung onto this yellow jersey. Not renowned as a climber he was one of the lead-out group, and avoided being swallowed up the peloton.
The Belgian increased his lead to second-placed French rider Julian Alaphilippe and other contenders, including Froome, by one minute and 25 seconds.
Elsewhere, there was disappointment for the French fans as Thibaut Pinot lost almost three minutes on an energy-sapping day.
Geraint Thomas remained 40 seconds behind team-mate Froome.
Stage seven result:
1. Steve Cummings (GB/Dimension Data) 3hrs 51mins 58secs
2. Daryl Impey (SA/Orica) +1mins 5secs
3. Daniel Navarro (Spa/Cofidis) same time
4. Vincenzo Nibali (Ita/Astana) +2mins 14secs
5. Greg Van Avermaet (Bel/BMC Racing) +3mins 04secs
6. Luis Angel Mate (Spa/Cofidis) +4mins 29secs
7. Geraint Thomas (GB/Team Sky) ST
8. Wout Poels (Ned/Team Sky)
9. Gorka Izagirre (Spa/Movistar)
10. Alejandro Valverde (Spa/Movistar)
Revised general classification after stage seven:
1. Greg van Avermaet (Bel/BMC Racing) 34hrs 9mins 44secs
2. Adam Yates (GB/Orica-BikeExchange) +5mins 50secs
3. Julian Alaphilippe (Fra/Etixx-Quick-Step) +5mins 51secs
4. Alejandro Valverde (Spa/Movistar) +5mins 53secs
5. Joaquim Rodriguez (Spa/Katusha) +5mins 54secs
6. Chris Froome (GB/Team Sky) +5mins 57secs
7. Nairo Quintana (Col/Movistar) same time
8. Warren Barguil (Fra/Giant)
9. Pierre Rolland (Fra/Cannondale)
10. Daniel Martin (Ire/Etixx-Quick-Step)