Tour de France: Martin claims maiden Tour stage

Froome was left to fight a defensive battle alone after the famed Sky train came off the rails on the first of the day's five categorised climbs.

He got out of the saddle at least half a dozen times to cover attacks off the front, playing a fascinating game of cat and mouse as Movistar's Nairo Quintana kicked out four times in the space of two kilometres on the final climb, the category one Hourquette d'Ancizan, before quickly being hauled back in each time.

As that squabble went on, Martin moved clear along with Jakob Fuglsang to take the long descent to Bagneres-de-Bigorre alone, with the Garmin-Sharp man winning in a short sprint to the line.

Froome finished 14th, 20 seconds back, as part of a group containing rivals Alejandro Valverde, Alberto Contador, Joaquim Rodriguez and Cadel Evans.

Froome's chief lieutenant Richie Porte had been dropped as part of Sky's troubles, eventually finishing more than 10 minutes down as Valverde moved into second place in the general classification, one minute and 25 seconds behind Froome.

Belkin's Bauke Mollema has moved up into third place overall, one minute 44 seconds back while Contador is lurking in sixth, a further seven seconds off the pace.

If Froome had dazzled with the brilliant way in which he seized control of the Tour on the climb to Ax 3 Domaines 24 hours earlier, this latest ride was equally impressive as he fought a lone battle amid a pack of predators.

Porte and Peter Kennaugh had played the key roles in delivering Froome to the front on Saturday but they both went missing on the first of the five categorised climbs a day later.

Kennaugh went in spectacular fashion, tumbling down an embankment after falling close to the side of the road and then emerging with extensive cuts on his arms.

Porte disappeared in less dramatic but equally alarming fashion, dropped on the first climb and, despite a big push on the category one Col de Peyresourde midway through the stage, he faded badly over the final two climbs of the day.

While the scrap at the front was absorbing so much attention, Martin saw his chance for a first career Tour win and he went up the outside of Froome and Quintana with five kilometres of that final climb to go.

Fuglsang responded to draw level and the two descended together, the Astana man leading the way into Bagneres-de-Bigorre.

With Fuglsang still narrowly ahead, there were nervous glances between the two - neither of whom had tasted victory here before - until Martin kicked out 250m from the line to leap in front of the Dane.

Fuglsang had no answer to the 26-year-old, who became the first Irish stage winner at the Tour since his uncle Stephen Roche in 1992.

Even if he was celebrating a landmark victory, Martin claimed his day had not gone exactly to plan.

"It didn't go perfect," he said. "The plan was to have me in a few contests in the start.

"But that didn't happen because Sky obviously didn't want me to go. We just wanted to have fun today. We love racing bikes and making racing exciting for people at home.

"If we win, we win, if we don't we make a good show. I think it was a very exciting stage and luckily I had the legs to finish the job.

"I was attacking on the first climb, and the second climb and I was thinking maybe I had wasted too much energy there but in the end it was okay."

If Martin's day did not go to plan, it is hard to say how far off the script Team Sky's got.

While Froome performed heroics to keep his rivals in check, Porte's struggles and Kennaugh's crash suddenly made a team so dominant 24 hours before look horribly fallible.

"That was a really hard day, one of the hardest I've ever had on a bike," Froome said.

"I did feel in control in that lead group. Tactically I was able to sit on the wheel of the various team leaders and follow them. It's quite normal for my team-mates to be feeling it a bit. They are human and they can't be doing it every day."