Cycling: Alberto Contador promises Tour duel after stunning return

Cycling's top stage racer Alberto Contador completed a dream comeback from a doping ban yesterday when he clinched his fifth Grand Tour title and second Tour of Spain.

Last Wednesday on what was theoretically a straightforward transition stage through hilly terrain in northern Spain, an audacious long distance attack by the 29-year-old Madrileno saw Contador grab the overall lead from fellow Spaniard Joaquim Rodriguez.

The Saxo Bank-Tinkoff rider then comfortably defended his advantage on Saturday's spectacularly steep mountain top finish of La Bola del Mundo and finished secure in the main pack in yesterday's largely ceremonial stage into Madrid, won by Germany's John Degenkolb.

On the backfoot for much of the race, Contador's victory is all the more remarkable given he completed a doping suspension at the start of last month . In July 2010 Contador tested positive for a minute quantity of the banned substance clenbuterol and, following a long legal battle and his protests of innocence, he was stripped of victories in the 2011 Tour of Italy and 2010 Tour de France.

Now Contador has put the ban behind him with a vengeance, claiming a triumph that sets him up as Bradley Wiggins' main rival in next year's Tour de France – a race which Contador has won twice, in 2007 and 2009.

If another Contador win in a three-week stage race can almost be described as business as usual – he is one of just five riders in cycling history to have pulled off the "Grand Slam" of victories in the Tours of France, Italy and Spain – what will be giving Wiggins and Sky much more food for thought is how he managed his latest victory.

Contador attacked on a seemingly insignificant climb mid-stage at a point where his rival was caught napping. That sort of unpredictable, aggressive racing was noticeably lacking from this year's Tour de France, and Contador's new-found versatility will force the British team to raise their game considerably next July.

"I won because I thought outside the box and I was courageous," Contador said. "I feel a real sense of release from pressure, liberated by this win."

Second last year in the Tour of Spain represented a breakthrough for Britain's Chris Froome, but the Sky rider could not repeat that in 2012, instead finishing fourth overall after his strong initial challenge faded out in the second week.

Froome and Contador – who has praised the Briton "for doing an amazing Tour [de France] and then riding himself into the ground here as he tried to challenge" – will cross swords again soon, in the world championship time trial next week in the Netherlands. As for the first of the Spaniard's much-anticipated duels with Wiggins, Contador and cycling fans will have to wait until next year.