CERCEDILLA, Spain (AP) Fabio Aru of Italy got the help he needed from his Astana teammates to finally break Tom Dumoulin and take the lead of the Spanish Vuelta on its penultimate stage on Saturday.
Barring an injury or incident during the traditional arrival to Madrid on the 21st and final stage, Aru is set to win the three-week Grand Tour after turning a six-second deficit to Dumoulin into a commanding advantage.
Spaniard Ruben Plaza broke away early and rode solo to win the 176-kilometer (109-mile) mountainous ride from San Lorenzo de El Escorial to Cercedilla that included four category-one climbs.
An attack by Aru supported by his teammates on the third of those ascents dropped Dumoulin, who had held his own in previous mountain stages but was now left to flounder without any of his fellow Giant-Alpecin riders.
Dumoulin finished the stage almost four minutes after Aru, falling to sixth place in the general classification at 3 minutes, 46 seconds behind.
Aru, who wasn't even Astana's top rider at the start of the race, broke into tears on crossing the finish line and embraced teammates Luis Leon and Mikel Landa, who proved critical to helping him beat Dumoulin.
''The team won this Vuelta,'' an emotional Aru said. ''My teammates gave it their all. They were exceptional, those who were in the breakaway, and Mikel Landa, who was always with me when I needed him.''
Aru's came into contention only after team leader Vincenzo Nibali was expelled from the race for holding onto a team car while trying to make up lost time during the second stage.
Dumoulin stuck with Aru and the more experienced climbers through three summit finishes in the high mountains before becoming the favorite when he took over the red jersey in Wednesday's time trial.
But the Dutchman showed his first signs of vulnerability on Saturday's third climb, letting Aru and Landa open up a small gap before he could close.
Having hurt his rival, Aru went for the decisive blow and surged up the mountain. Dumoulin could only watch as the other top riders including Joaquim Rodriguez, Nairo Quintana, and Esteban Chaves left him all alone to struggle to the Morcuero summit.
''It was too much today,'' Dumoulin said. ''After the first attack by Aru I had difficulties countering him and closing the gap. I was on the limit. When he went again it was over, and there was a gap at the summit. In the valley, Astana pulled with three guys and I knew it was over.''
Rodriguez moved into second place overall, 1 minute, 17 seconds behind Aru.
Rafal Majka was third overall, 1:29 back.
Plaza rode alone for more than 100 kilometers to claim the stage in 4 1/2 hours for his Lampre-Merida team.
Sunday's stage is a traditional ride into the capital, a 99-kilometer (61-mile) route from nearby Alcala de Henares.