Chris Froome described this year's Vuelta a Espana as the toughest Grand Tour he has ridden as he all but completed the double.
The Team Sky rider holds a lead of two minutes, 15 seconds after a grueling 117.5-kilometre stage 20 from Corvera de Asturias to Alto de l'Angliru.
Set to complete the Tour de France-Vuelta double, Froome, 32, said this year's race in Spain was probably his most difficult.
"I have to say it's probably the toughest Grand Tour I've ridden, this year's Vuelta. Every day was something else," the Brit said.
"It's just such a big relief to have now got to this point and I'm looking forward to getting to Madrid.
"I've been trying for years and I've been second three times, so to win the Vuelta now is incredible."
The day belonged to Alberto Contador, who claimed a stage victory in what is his final professional race.
Froome paid tribute to the Spanish two-time Tour champion, saying: "Today was an extremely fitting way for him to say goodbye.
"To attack on that descent and keep the lead to the finish, chapeau. He brings so much to the races.
"It's going to be easier for me when he's not around but I have to respect what he did."