Armstrong so driven

As Lance Armstrong donned his first yellow jersey of the Tour de France after a third stage win in four days, he revealed the central motivation for his latest devastating ride: the death of a team-mate in a racing accident six years ago, Fabio Casartelli.

Casartelli suffered fatal head injuries in a crash on the Portet D'Aspet descent in the 1995 Tour, becoming the first rider to die in the race since Briton Tom Simpson in 1967. Armstrong at the time was team leader of the young Italian's squad, Motorola.

The following day's stage was cancelled in memory of Casartelli, but Armstrong won 48 hours later in Limoges in a lone break. He crossed the line with a single right finger pointing at the sky in memory of his friend, and yesterday he made the same gesture on reaching the finishing line one minute ahead of his closest rival, Jan Ullrich.

Yesterday, the Portet d'Aspet was the first of six viciously steep Pyrenean climbs – which between them forced seven more to drop out out of the race – and it finished with the 10.3km ascent to Pla D'Adet ski station.

"I had never ridden past the memorial to Fabio there in a race and when I did so I decided straight away I wanted to win," Armstrong revealed.

The Texan finally took off with five-and-a-half kilometres to go on the final climb, and he quickly stormed past an early breakaway, Laurent Jalabert, "so easily it was like a dream," the Frenchman admitted later. Armstrong had two missions to accomplish on yesterday's 194km stage: to close on Frenchman François Simon, who was still nine minutes ahead of him overall, and to repel Ullrich's unsuccessful but insistent attacks.

But as the Armstrong group of some 20 riders closed on the exposed summit Peyresourde, the second-last climb of the stage, Ullrich made a strong "over-the-top" attack.

The American was right behind the German on the descent, so close in fact that he had a front-row view when the 2000 Olympic road champion misjudged a left-hand bend and shot into a steeply sloping hayfield below. There was a flash of steel from behind the crash barrier as the German's bike somersaulted through the air, but despite gaining some impressive black skidmarks on his jersey, Ullrich was otherwise uninjured.

Armstrong did what he called "the decent thing" and freewheeled down so Ullrich could catch up, which also allowed a small group of riders, including Joseba Beloki, currently gunning for repeat of his 2000 place on the Paris podium, to rejoin.

Beloki and Ullrich inconclusively crossed swords on the next climb, the Val Louron, but it was Jalabert who had French television commentators jumping out of their seats when he took a tumble on the last corner of the lethally twisty descent. He was uninjured, but his lead had dropped to three minutes.

If "Ja-ja" had any hopes of taking a third stage, Armstrong's long-term strategy proved fatal for him.

"My team-mate Roberto Heras had to drive hard again at the foot of the Pla d'Adet because Simon was only seven minutes behind," Armstrong explained later. Ullrich then contributed to Jalabert's downfall by attacking a third of the way, but the champion had no problems responding.

But Ullrich was left behind as Armstrong tore away on his own and put an end to Jalabert's day-long break one kilometre later. "Maybe it's because I have trained harder, but I don't think I've ever felt this good before," said Armstrong, now 3min 54sec ahead of his nearest rival, Simon.

Ulrich, 5:13 down and all but condemned to taking second for a fourth time in Paris, would be pushed to disagree.