Contador (Astana) and Schleck (Team Saxo Bank), the 2009 winner and runner-up, respectively, distanced themselves from their yellow jersey rivals on the 204.5-kilometre ninth stage from Morzine-Avoriaz to Saint-Jean-de-Maurienne.
Schleck beat Contador to the maillot jaune after leader Cadel Evans (BMC Racing) imploded on the 97th Tour’s first hors categorie (beyond category) climb, the 25.5km Col de la Madeleine.
Sandy Casar (FDJ) won the stage in a sprint finish, but the more significant battle in the race to Paris was taking place between Contador and Schleck, the winner of Sunday’s stage.
The duo finished two seconds behind Casar and with 11 days of racing remaining, Schleck now holds a 21-second lead over Contador, with Samuel Sanchez (Euskaltel-Euskadi) third, 2mins 45secs behind Schleck.
With a four-man escape – one they would catch on the long descent into Saint-Jean-de-Maurienne – reaching the Madeleine summit 2:10 ahead of them, Schleck and Contador took part in an extraordinary duel. There were times when each meandered across the narrow Alpine ascent, daring each other to dart ahead. Schleck took the initiative, but both looked strong and it appears to be a race between the duo for the Tour title.
Schleck said: “If he wants to win this, he’s got to attack me.”
Contador is a stronger time-trial rider than Schleck and with a 52km race against the clock on the penultimate day, the Team Saxo Bank leader must gain more time on his Spanish rival in the mountains.
Schleck added: “In a race like the Tour, when there is an opportunity you have to take it.
“That’s what I did today. I still think the Pyrenees will decide the Tour, but it’s easier for me now because I have only one rider to look out for.
“I don’t think other riders can come back to us.”
Schleck will wear the Tour race leader’s yellow jersey for the first time in his career on today’s Bastille Day stage, the 179km 10th stage from Chambery to Gap.
Ireland’s Nicolas Roche put in another impressive performance in the mountains, coming in 25th in a group 4mins 55secs behind Casar.
The AG2R La Mondiale rider lies 17th in the overall standings, 7mins 44secs behind leader Schleck.
Following his capitulation on Sunday, Lance Armstrong (Team RadioShack) finished 18th, 2mins 50secs behind in a group which included Ivan Basso (Liquigas-Doimo).
Team Sky’s Bradley Wiggins finished 30th, in the same group as Roche.
Team Sky leader Wiggins has reevaluated his Tour goal after a second day of toiling in the Alps.
“I don’t want to give up and throw my toys out of the pram, finish at the back or go home,” said Wiggins.
“I’m going to just push on every day and maybe just recalibrate, say top 10 is now the goal. It’s been an exciting Tour up to now. At least you know where you stand — you haven’t got to wait two and a half weeks to know where you stand.”