AUBENAS, France — After three weeks and thousands of miles of riding, it all comes down to this: a soaring bald mountain in Provence where the Tour de France can be won or lost.

The fabled and dreaded Mont Ventoux today provides a dramatic climax to Lance Armstrong's comeback Tour — and teammate Alberto Contador is expected to keep the yellow jersey.

The main question in the 103.8-mile Stage 20 from Montelimar to the ascent that Armstrong calls the toughest in France is whether he'll be on the podium with the Spaniard when the race finishes tomorrow on the Champs-Elysees in Paris.

Yesterday's relatively flat stage from Bourgoin-Jallieu to Aubenas did little to change the race standings, though an ever-opportunistic Armstrong shaved off four seconds to his deficit to Andy Schleck in second.

"Big day 2morrow ..." Armstrong wrote on his Twitter account. "The 'Giant of Provence' Mt. Ventoux. Know it well, we're old friends but haven't always gotten along."

Britain's Mark Cavendish won the stage in a sprint, collecting his fifth stage victory at this race — the most by a rider in a single Tour since ... Armstrong in 2004.

Armstrong trails Contador by 5 minutes, 21 seconds. Schleck, of Luxembourg, is 4:11 off the leader's pace.

While the 37-year-old Armstrong has an outside — if unlikely — shot at overtaking Schleck, Armstrong's big concern are those behind him: Bradley Wiggins of Britain is only 15 seconds behind him, and Schleck's older brother Frank is 38 seconds back of the Texan, who has won the Tour seven times.