With just 10 kilometers to go on the steep climb to Courchevel during yesterday’s 10th stage of the Tour de France, Lance Armstrong’s heir apparent, Yaroslav Popovych, put the hammer down.

The Discovery Channel riders had set a ferocious tempo up the 22 km climb, and their pace continually shrunk the group of leaders. Apart from Armstrong, Popovych was the last of the riders in gray and blue, and he hopped out of the saddle and upped the tempo. His goal was to exhaust the lead group and pave the way for an Armstrong triumph.

When Popovych pulled off, spent from the effort, and Armstrong took over, only three riders could stay with him: Alejandro Valverde and Francisco Mancebo of the Iles Baleares team and Stage 9 winner Mickael Rasmussen (Rabobank). At the summit, Valverde sprinted around Armstrong for the stage win, but by then, the six-time defending champion had a commanding lead in the overall standings.

Even those who never doubted that Armstrong could secure a seventh consecutive Tour victory had to marvel at the way he recaptured the overall lead yesterday. As he has done so many times before, the greatest Tour champion in history quieted his detractors with a jersey-snatching climb into Courchevel, leaving his would-be rivals sucking Alpine air.

Yesterday’s stage, scheduled to stretch 192.5 km from Grenoble to Courchevel, was especially unpredictable. It didn’t even start in Grenoble. A planned protest of French farmers at the starting line moved the pack 11 km down the road to Brignoud. Even there, Tour officials encountered too many of their irate countrymen shouting complaints about wolf populations, and so the stage was shortened a further 3 km.

Spectators were focused primarily on three teams at the start: Discovery Channel, T-Mobile, and CSC, the last of which had the yellow jersey – on the back of Jens Voigt – and hoped to transfer it by day’s end to their captain, Ivan Basso. Two riders – Joost Posthuma (Rabobank) and Laurent Brochard (Bouygues Telecom) escaped right at the start. The group eventually grew to seven riders, and gained a 10-minute lead on the peloton.

On the first climb of the day Cormet de Roseland, Oscar Pereiro (Phonak), Stefano Garzelli (Liquigas-Bianchi), and Jorg Jaksche (Liberty Seguros waged a potentially dangerous attack. They were quickly followed by Mancebo, Valverde, and Oscar Sevilla (T-Mobile), which stirred up a chase from the peloton. The three Spaniards were quickly brought back into the fold, but Pereiro and Jaksche escaped to the breakaway group. Armstrong reacted by sending his riders to the front, and the Discovery team took control of the peloton at the top of the climb.

With the heat in the valley approaching 90 degrees Farenheit, they cranked up the peloton’s speed to an exhausting pace – one they knew Armstrong could handle, but many others could not – and dropped Voigt and Euskaltel’s leader Iban Mayo. Other would-be contenders soon followed suit: Bobby Julich (CSC), Santiago Botero (Phonak), and even T-Mobile’s Alexandre Vinokourov, once thought to be the clearest danger to Armstrong’s title. “I’m not sure what happened in the mountains,” the Kazakh said afterward. “It’s been a very bad day for me.”

Vinokourov’s teammate and Armstrong’s perennial rival, Jan Ullrich, suffered tremendously. Ullrich was still in pain from a hard crash on Sunday, but conceded that he could have done little to challenge Armstrong.

“We were really looking forward to today’s stage, but it was too much for my legs,” said Ullrich, who crashed hard on a descent in Sunday’s stage. “My ribs were hurting today and it hurt a little to climb, but it didn’t matter. I would have lost two minutes anyway.”

The time gaps at stage end were impressive. Basso lost 1:02; Ullrich and his teammate Andreas Kloden 2:18; Vinokourov 5:18; Roberto Heras (Liberty-Seguros) 9:49; Iban Mayo (Euskatel) 21:31; Voigt 31:29.

In some ways, yesterday’s stage can be seen as a changing of the guard at the Tour. Valverde launched himself into cycling’s spotlight, and fifth place overall, by edging past the champion on the final push. He has shown himself to be a fine sprinter and outstanding climber, a rare combination that has turned heads in the cycling world.

“With Valverde, everybody has seen the future of cycling,” Armstrong said, on this, his farewell tour. “He’s fast, he’s strong, he’s intelligent. It’s impressive.”

Rasmussen, too, has impressed, and he is now in second, at only 38 seconds. He and Armstrong seemed calm and comfortable as the field fell apart yesterday. The Dane came to the Tour to win the climber’s competition, but now has to be thinking about a place on the podium in Paris. He is not a great time trialist, so we can expect him to attack in all the mountain stages to gain time over rivals.

Stage 11 today is another tough day in the mountains: a 173 km haul from Courchevel to Briancon. It includes two beyond-category climbs, the Col de la Madeleine and the Col du Galibier – the highest point in this year’s Tour – as well as the tough Category 1 Col du Telegraphe, the traditional staging ground for the Galibier.

The stage ends in a 40 km descent into Briancon, which should allow the top climbers to regroup after the giant of the Alps. This is the hump day of the Alps in every sense, with another two steep peaks to climb before undulating out on Thursday into the relative flatness of Provence.