Dan Martin became Ireland's first Tour de France stage winner since Stephen Roche in 1992 when he won today's 168.5km mountain stage from Saint-Girons to Bagnères-de-Bigorre in the Pyrenees.
The Garmin-Sharp, Movistar and Saxo-Tinkoff teams blew the peloton apart in the first of five climbs on a searing hot day, with overall leader Chris Froome soon finding himself isolated.
The moves eliminated Froome's lieutenant Richie Porte, who lost his second place overall.
Martin and Denmark's Jakob Fuglsang formed a two-man breakaway and they timed their effort to perfection, controlling their advantage over the peloton.
But, in a typically tactical finish to the ninth stage, the Garmin-Sharp rider made his move for home at the final turn and had plenty in hand as he hit the line ahead of the gallant Dane, with the peloton, headed by Poland's Michal Kwiatkowski, 20 seconds back.
In the overall classification, Froome retained the leader's yellow jersey, while Martin is up to eighth place, two minutes and 28 seconds behind the leader.
Nicolas Roche finished in 156th place, in a group just over 26 minutes behind Martin.
That leaves him in 44th spot overall, 30:10 behind Froome.
Birmingham-born Martin became only the fifth Irish rider to win a Tour stage, and the first since his uncle's victory on stage 16 of the 1992 Tour in La Bourboule.
"Every win is important and special in its own way," the 26-year-old said.
"It was such an incredible day today because this team Garmin-Sharp shows such a team spirit.
"Everyone gave 100 per cent today and some of the guys nearly missed the time limit because they gave so much for my victory. We decided this morning on the bus that I was going to try and win the stage and we've succeeded so it's incredible."
Martin and Fuglsang made their move as the main contenders at the front of the race were engaged in an absorbing game of cat and mouse, with Froome anxiously - and successfully - defending his yellow jersey against the likes of Alejandro Valverde and Alberto Contador, with his Team Sky team-mates nowhere to be found.
Although Fuglsang led the pair into town and towards the finish line, Martin was close behind and, after some nervous glances between the pair, he kicked out 250 metres from the line and Fuglsang could not answer.
"It's hard to describe how it feels; it's more relief actually because I knew I was the favourite coming into the sprint and I was quite confident, but I still had to do it," Martin added.
"To come across the line knowing that I've won a stage of the Tour de France is amazing. In the end, the scale of the event wasn't on my mind - it was just another bike race.
"I was so focused on his wheel and beating that guy in the sprint that I didn't even look behind once to see where the peloton was. It was just a case of focus on the finish line and get there first."
While this was Martin's first taste of Tour success, it was not his first in a Grand Tour as he won stage nine of the Vuelta a Espana in 2011, and he called on that experience today.
"I think there was a calmness that I developed in the sprint, rather than confidence," he said. "I've always had that sort of calmness, when I won the ninth stage of the Vuelta it was much the same sort of feeling.
"In the big situations I seem to be able to relax very well and just be in control and it pays off."
Martin follows in the footsteps not only for Roche but also Sean Kelly, Seamus Elliott, and Martin Earley in winning a Tour stage.
Martin was mentioned as an outside contender for this year's mountainous Tour thanks to his climbing ability and a proud uncle - who won the Tour in 1987 - tipped him for future success.
"The sky's the limit," Roche said. "He can challenge for the podium in the next few years."