Ullrich and Armstrong are set to fight it out to the finish

Tour de France legend Lance Armstrong dismissed talk of his possible demise with a storming victory on Monday.

There had been suggestions that the four-times winner was on the wane after a number of below-par displays in this year's race.

But the American showed he had lost none of his brilliance or self-belief by winning stage 15 by 40 seconds despite falling when his bike's brake lever got entangled in a spectator's bag.

Armstrong entered the stage just 15 seconds ahead of the chasing pack but is now a strong favourite to claim his fifth Tour de France crown after extending that advantage to more than a minute with Tuesday a rest day.

Jan Ullrich is Armstrong's closest rival, but the Bianchi rider is 67 seconds off the lead with just five stages left.

"It's still a wide open race," insisted the German, who will hope he can climb some time back in Saturday's time trial.

And he has every reason to be upbeat.

Armstrong wins despite fall

Ullrich beat Armstrong by 90 seconds in the first big time trial of the Tour last week.

Monday's performance only enhanced Armstrong's reputation as one of cycling's all-time greats.

Following a disappointing display in Friday's time trial, the American's reign looked as though it was coming under serious threat.

But just when his obituaries were about to written, he bounced back in stunning fashion to leave no-one in any doubt about his pedigree.

I wish I could have some uneventful days Lance Armstrong

Armstrong needed a helping hand from former team-mate Tyler Hamilton before taking a tight grip of this year's race.

Hamilton slowed down the favourites group to allow his fellow American to catch up following his crashing fall.

But once he was back on terms, Armstrong left his rivals trailing with a typical gutsy show of strength.

Overall standings

As Armstrong swept to victory, the challenge of his closest rivals, Ullrich and Alexander Vinokourov, appeared to melt away.

Vinokourov, who is now two minutes 45 seconds off the lead, feels the Tour is now a straight fight between Armstrong and Ullrich.

A lot of people were doubting him this morning but he's a fighter Tyler Hamilton on Armstrong

"I wish good luck to Jan, who is a very close friend of mine," said the Telekom leader.

"He's very strong right now and probably at his very best ever. As for Armstrong, he's not too far from his best either now."

Hamilton, riding with a broken collarbone after crashing in stage one, reckons Armstrong will take some stopping.

"I could see today that Lance had very good legs and you've got to give him credit for fighting back," said Hamilton.

"A lot of people were doubting him this morning but he's a fighter and I was happy to see him have good legs."