It was the same time swing which Contador garnered on Monday's 15th stage, when he surged forward as Schleck's chain slipped on the ascent of the Port de Bales in the Pyrenees.

Had the Spaniard waited - as is conventional when a rival suffers a mechanical problem - the duo would be tied on time on today's final stage, which is traditionally a procession to the Champs Elysees before a sprint finish.

Today's 102.5-kilometre 20th stage from Longjumeau to Paris began in surreal fashion when Lance Armstrong - riding in his 13th and final Tour - and his Team RadioShack squad were told to change their race jerseys.

Today's stage was the last for the man who dominated the race from 1999 to 2005 and the cancer survivor and his team wore black jerseys featuring the number 28, to signify the 28 million people worldwide dealing with the disease.

Race organisers ordered Team RadioShack to revert to their original red and grey jerseys, to the apparent annoyance of Armstrong.

Contador, wearing the race leader's yellow jersey, then posed with a flute of champagne before a staged sprint with Schleck.

The 25-year-old Team Saxo Bank rider played along, before looking down at his bike.

He radioed to his team car, then dropped back behind the peloton where he switched his bike.

In 2009, Schleck finished four minutes 11 seconds behind Contador in second place.

Today the Luxembourg rider is poised to finish as the race runner-up for the second successive year.