PUERTO DE ANCARES, Spain (AP) — Alberto Contador surged past Chris Froome to win the mountainous 20th stage of the Spanish Vuelta on Saturday and increase his lead of the grand tour heading into its final day.

Contador stayed close to Froome as the former Tour de France winners shed the rest of the field on the special-category ascent to the Puerto de Ancares summit.

The Tinkoff-Saxo rider then used a final push to power by Froome and win the demanding 186-kilometer (115-mile) ride starting in Santo Estevo de Ribas de Sil that included four category climbs. The Spaniard could not help smiling brightly as he parted the crowd lining the road and left Froome behind, knowing he was closing in on what would be his sixth grand tour victory.

Contador crossed the finish line 16 seconds ahead of Froome and will have a lead of 1 minute, 37 seconds heading into Sunday's concluding stage — a 9.7-kilometer (6-mile) individual time trial in Santiago de Compostela.

"My strategy was simple, as long as my legs responded," Contador said. "I had to stay next to Froome and not let him get out of sight. I had an advantage of already being ahead, and now I couldn't be happier."

Contador curbed his expectations coming into the three-week event after recovering from a broken right shin that knocked him out of the Tour on July 15.

Now he is on the verge of winning his homeland's biggest race for the third time after victories in 2008 and 2012.

"This is a great victory for me," he said. "We were able to open up a gap that, barring a mishap, should win me the Vuelta. But we still have to wait until Sunday."

Sunday's stage in Santiago, better know for being the end point of the Way of St. James pilgrimage route, will be the second individual time trail of this edition. Contador took the race lead during the first time trial on the 10th stage after Nairo Quintana crashed.

Alejandro Valverde will enter the final day in third place, at 2:35 behind Contador. Joaquim Rodriguez, who attacked the other leading riders on Saturday before fading at the end, trails Contador by 3:57.