The 31-year-old cancer survivor and Spanish great Miguel Indurain (search) are now the only two riders to win the sport's most grueling and prestigious race five times straight — a record Armstrong plans to break next year.
Savoring his triumph, Armstrong sipped from a flute of champagne as he completed the largely processional final stage of the race past Paris landmarks. He toasted his achievement with a "cheers!" as he rode, wearing the overall leader's yellow jersey that he had so ardently coveted.
"It's incredible to win again," he said.
The indefatigable Texan overcame illness, crashes, dehydration, team and equipment problems, and uncharacteristic bad days during the 23-day, 2,125-mile, clockwise slog around France to win by his smallest-ever margin — 61 seconds over five-time runner-up Jan Ullrich of Germany.
Armstrong, who had never won by less than six minutes, said his fifth title was "definitely the hardest" but "feels better" than the previous four, when he demoralized rivals by dominating in lung-burning mountain ascents and super-speedy time trials.
A staunch perfectionist, Armstrong said the closeness of the victory was already motivating him to come roaring back in 2004.
"The other years I won by six, seven minutes. I think it makes it more exciting and sets up an attempt for No. 6," he said. "Before the Tour started I was very confident about winning. But before next year's Tour, I won't be so confident."
The intense rivalry between Armstrong and Ullrich, the 1997 Tour winner, turned 'Le Tour' into a gripping festival of cycling after four years when Armstrong was all but assured of victory days before the finish on the Champs-Elysees (search).
This year, he only sewed up his win in a rain-soaked time trial Saturday, the penultimate day, when he managed to stay upright on the slippery road while Ullrich skidded and crashed, ending a squarely fought duel.
So action-packed was this Tour that Armstrong was prepared even Sunday, on the largely processional final stage, for the unexpected.
"If a plane landed in the race I wouldn't be surprised," he said before setting off from the Paris suburb of Ville d'Avray on the 92.4 mile ride through streets packed with cheering spectators.
Armstrong, who underwent surgery and chemotherapy for testicular cancer (search) diagnosed in 1996 that had spread to his lungs and brain, said his hard Tour battle had humbled him.
"It makes me appreciate this victory and the other victories more because you realize the best form and the best conditioning are not a given," said Armstrong, who favors the Tour above all other races and prepares meticulously for it.
Ullrich, returning from two knee operations and a ban for taking amphetamines in a disco, came into the Tour saying he did not expect to win. But as it became evident that Armstrong was not at his best, the German and other key rivals pressured the Texan as never before, attacking him on grueling mountain stages in the Alps and Pyrenees.
The German was most devastating in a time trial July 18, when he sliced a whopping 96 seconds off Armstrong, who had never before been beaten by Ullrich in a race against the clock at the Tour.
Armstrong wilted in scorching heat that day in the sun-roasted south of France, hanging grimly onto second place but losing about 11 pounds in weight through dehydration. It was a crucial mistake that prompted speculation that at 31, he was too old to win again.
But Armstrong stormed back three days later on a mist-shrouded 8.3-mile ascent to the Pyrenean ski station of Luz-Ardiden (search), one of the Tour's hardest climbs.
He recovered from a fall, caused by a spectator's outstretched bag that caught his handlebars, to roar past Ullrich, who sportingly waited for him to get back on his bike. Other than a victory in the team time trial with his U.S. Postal Service squad, it was Armstrong's only stage win of this Tour and marked a turning point. From then on, Ullrich was chasing Armstrong's lead.
"At the start of the climb, I knew that that was where I needed to win the Tour," Armstrong said. "At the finish I was confident that that was enough."
Armstrong said that in previous years, his preparations for the following Tour begin almost straight after his victory celebrations. Not this year.
"This Tour took a lot out of me," he said. "I need to step back from cycling and from the races and relax a little bit and focus on 2004 in due time."