SESTRIERE, Italy (AP) Alberto Contador had his overall lead sliced in half on the penultimate day of the Giro d'Italia on Saturday, although the Spaniard remained on course for the title after the 20th stage.
Contador was dropped on the grueling climb up a dirt road on Colle delle Finestre as rivals Fabio Aru and Mikel Landa sped clear.
Aru, who moved back into second place overall with victory in Friday's 19th stage, soloed to a second successive win to close the gap to 2 minutes, 2 seconds.
''I can't believe it still. After I've had a few bad days and I've suffered, it's absolutely wonderful to win again and get that second place,'' said Aru, who is from Sardinia. ''I train at Sestriere and I am very attached to this area ... There were so many fans who were encouraging me along the edge of the road that I felt that I was at home.''
Ryder Hesjedal was 18 seconds slower than Aru at the end of the 199-kilometer (124-mile) leg from Saint-Vincent to Sestriere, with Rigoberto Uran 0:24 behind the Italian.
Aru's Astana teammate Mikel Landa remained third overall, 3:14 back, ahead of Sunday's flat finish in Milan. Landa also won the Cima Coppi competition, as he was first up the Finestre - the highest point of this year's Giro at over 2,100 meters (2,295 yards).
The climb included 42 hairpin turns along 18 kilometers (11 miles), with gradients peaking at 14 percent.
Contador, who never panicked despite having a bad day, gave a little fist pump as he crossed the line, knowing that the Giro title is still likely his - and the first part of an impressive double.
He had started the day more than four minutes ahead of Aru but crossed the line 2:25 off the pace.
Contador is attempting to become the first rider since Marco Pantani in 1998 to win the Giro and Tour de France in the same year. He has had to dig deep during a troublesome three weeks in Italy, after enduring crashes and a dislocated shoulder, and is likely to face stiffer competition in the Tour.
''I didn't feel well, probably because of all the accumulated effort, but I knew I had a good advantage in the general classification and, even though there is still a long way to go to the finish, I preferred to climb at my pace,'' Contador said.
''There was never a moment that I thought the jersey was at risk ... I'll allow myself a good dinner tonight, even though I have to watch my weight for the Tour. This Giro is practically won now, there's just tomorrow's stage, so I'm already thinking of my next goal.''
A two-time Tour champion, Contador won the Giro in 2008 and was also triumphant in Milan in 2011 but was stripped of that title for testing positive in the 2010 Tour.