Roche, who now lies 19th in the general classification, was aggressive from the outset once again and forced himself into the day’s 16-man breakaway that surged clear of the peloton after 40 kilometres.
That group rode well together, benefiting from having 12 teams represented and all collaborated well to open up a maximum advantage of nine minutes.
The Ag2R La Mondiale rider has spoken via his twitter account all week, since his nightmare showing last Saturday where he dropped out of contention for a top 10 overall finish, about his desire to go on the offensive in the hope of garnering a first stage win.
Yesterday the 27-year-old looked a good bet for same as he rode a good tempo at the front, dropping several of his companions over some of the steepest climbs of this year’s race.
However, as soon as Andy Schleck forced his way into that break after an audacious attack of his own with 60 kilometres to go, the Irishman began to struggle under the relentless pace being set by the Luxembourg rider.
Eventually, with less than 15 kilometres to go, the inexorable rhythm of Schleck shelled Roche and the new favourite for the race did likewise to the last remaining breakaway rider, Maxim Iglinskiy (Astana), in the final 10 kilometres.
From there to the finish, as the race went up the Galibier for the highest summit finish in the history of the event, it was all about how much time Schleck could pull back on the other race favourites. Behind them, as the lead increased to four minutes, Contador moved to the front of the yellow jersey group, with Evans, Frank Schleck and Ivan Basso (Liquigas) also present.
The yellow jersey group hesitated, allowing others to reel them in. With around 15km of the ascent still to go and with no-one apparently willing to take responsibility to lead the chase it all played perfectly into the hands of the younger Schleck.
Evans eventually seized the initiative and attacked behind, stretching the peloton into a long line.
The Australian was towing along Voeckler and the other leading riders, with Contador around 10th in the group, but Samuel Sanchez (Euskaltel-Euskadi) lost contact and faded.
With 5km to go Andy Schleck had an advantage of 3:15, with Evans still leading the pursuit, but with 3km to go on the climb, Contador had to fight to stay with Evans, Voeckler – supported by Pierre Rolland – Frank Schleck, Basso and Damiano Cunego (Lampre-ISD) before being dropped.
Andy Schleck suffered in the finale, almost coming to a halt with 200m to go, before celebrating victory.
But the maillot jaune proved elusive as Voeckler dug deep to retain the race lead, by just 15 seconds.
“I suffered but I followed the favourites,” he said. “To keep the yellow jersey was beyond my expectations at Luz-Ardiden, then again at the Plateau de Beille, and now here at the Galibier.”
Voeckler promised to fight again at l’Alpe d’Huez today, “but everyone knows that Andy Schleck is a better climber than me,” he noted. “I don’t want to think about tomorrow. I only want to take a rest.”
Today’s 109.5km 19th stage from Mondane Valfrejus to Alpe-d’Huez represents another opportunity for the overall favourites – and perhaps the last chance for the Schleck brothers to gain time on their rivals, given their inferior time-trial ability.