After three daunting weeks of crashes, biting cold, fog and searing heat, he is set to become the Tour de France champion again.
The Spaniard all but captured his third title in four years Saturday by holding off a full-bore challenge from his main rival, Andy Schleck of Luxembourg, in a 32-mile individual time trial in the next-to-last stage. Sunday's ride into Paris is a mostly ceremonial affair.
"I am very moved ... It was a difficult Tour and I'm very happy," a tearful Contador said.
He took a deep breath and his hand trembled as he fired an index finger - the trademark gesture by the rider nicknamed "El Pistolero" - to fans after donning the yellow jersey one more time.
"I think it's the first Tour that has given me so much emotion, you can't imagine," he said.
Contador wasn't in top form, but did what he had to. The defending champion extended his lead over Schleck from eight seconds to 39 in a stage won by Fabian Cancellara of Switzerland. Now Contador surely gets to wear yellow on the Champs-Elysees. And as the unquestioned leader of his sport at 27 years old, he remains on track for a possible challenge to Lance Armstrong's record of seven Tour wins.
Barring a wild turn of events, Contador awaits a coronation in the 20th and final stage on Sunday - a 64-mile ride from Longjumeau to the famed Paris thoroughfare. Any attempted attacks by riders would likely be quashed by Contador and his Astana teammates.
Contador will have won the Tour without winning a stage. He'll become the first champion to have done that since Greg LeMond of the U.S. won the last of his three titles in 1990 - not counting 2006 - when Oscar Pereiro of Spain inherited his title only after American Floyd Landis lost it for doping.
Contador acknowledged this wasn't his best Tour.
"Cycling is not like mathematics. There are moments when you are very well-prepared and everything runs smoothly. But this year, maybe I was not in the best shape really," he said.
"Today I was not feeling so well: I didn't sleep well, I had a stomachache," Contador said through a translator, before adding: "Eventually, things went pretty well."
Schleck, who is poised to finish second to Contador for the second straight year, had no regrets.
"Beating Contador is not easy, but I tried everything," Schleck said. "I am happy, and I'll come back next year to win." "I think I did the best time-trial of my cycling life so far," he added.
During the race, Schleck was hindered by the withdrawal of his older brother and teammate. Frank Schleck broke his collarbone in a crash over the cobblestones in the third stage along the Belgian-French border.
The 39-second margin is exactly the time that Schleck lost to Contador in the controversial 15th stage on Monday. That's when the Luxembourg rider's bike chain became entangled in a final Pyrenean climb - and Contador sped on.
Some called it a breach of cycling's often-unclear etiquette, which calls for riders to respect the yellow jersey - Schleck was wearing it then - in times of uncontrollable mishaps like a crash.
That day, Contador took the jersey and has worn it since.
Schleck was at first angered over Contador's move to bolt ahead, but he later appealed to fans not to jeer the Spaniard. The two riders have vacationed together and Schleck calls him a friend.
Saturday's stage seemed destined for drama: Riders set off one by one down a starter's ramp for a race against the clock and the podium positions on the line.
It was the final showdown in a race that's been a two-man battle since Schleck took the yellow jersey in the Alps in the ninth stage. A day earlier, Armstrong - once a possible contender - fell from contention after crashing and struggling in two Alpine climbs.
"We had suspense until the last moment," Tour director Christian Prudhomme said.
Long written off as not being among the best in time trials, Schleck and many in cycling believed he would need the time trial of his life, or for Contador to have a really bad day or encounter some mishap.
At the first time check Saturday, 11 miles, Schleck erased two seconds off the deficit to Contador, though both men were still about 90 seconds behind Cancellara.
But by the second and third time checks, Contador gained speed and momentum on his rival. By the second check, 22, miles, he was seven seconds faster. By the third, near the finish, he led by 17 seconds.
"Everybody knows it was not like last year when Contador was just better than me," Schleck said. "In the climbs, we were pretty equal. But it's three weeks and the time all counts."
Cancellara, one of the world's top time-trial riders, was 17 seconds ahead of Tony Martin of Germany. Bert Grabsch of Germany was third, 1 minute, 48 seconds behind the winner. Contador was 35th, 5:43 back, while Schleck finished 44th, 6:14 behind Cancellara.
Denis Menchov of Russia, who won the 2009 Giro d'Italia, overtook Samuel Sanchez of Spain to wrest third place overall. Menchov began the day in fourth, 21 seconds behind Sanchez. The Russian finished 11th - 3:51 back of Cancellara while Sanchez was 40th, 5:51 behind. Overall, Menchov now trails Contador by 2:01, and Sanchez fell to fourth, trailing his compatriot by 3:40.
Armstrong is set to go out with a whimper in his last Tour. The 38-year-old Texan once dominated time trials. But he finished Saturday's stage in 67th place, 7:05 back of Cancellara. Overall, he is 23rd - 39:20 behind Contador, his former teammate and rival.
Armstrong returned to a RadioShack team car and left without speaking to reporters after the stage.
In last year's Tour, tensions flared between Contador and Armstrong, who finished third in his Tour comeback after four years of retirement from the race he dominated from 1999 to 2005. Now, the two enjoy a "mutual respect," Contador said.
Armstrong still can walk away with pride: His RadioShack squad is set to win the team competition.
In the other race categories - assuming the riders and teams finish Sunday - France's Anthony Charteau has clinched the polka-dot jersey for the race's best climber. Schleck, 25, will take home the white jersey for being the best young Tour rider for a third consecutive year.
The last question concerns the green jersey, which is given to the best sprinter. Alessandro Petacchi, a 36-year-old Italian, looks likely to win that shirt.
After more than 2,175 miles of racing, Contador is poised for another narrow victory. In 2007, when he won for the first time, he beat Australia's Cadel Evans by only 23 seconds. In that Tour, the tightest in the race's 107-year history, American rider Levi Leipheimer was third, 31 seconds behind the Spaniard.
This edition is set to become only the fifth Tour decided by less than a minute. The record is the eight seconds - by LeMond over Laurent Fignon of France in 1989.
The result has fanned Schleck's confidence for a fight another day.
"Unfortunately it was not enough to beat Alberto, but he was pretty exhausted at the end," he said. "I think we had a nice fight out there between him and me today. I'll be back to win this."
Associated Press Writer Naomi Koppel contributed to this report.