MADRID - Fabio Aru all but secured a debut grand tour triumph when he left overnight leader Tom Dumoulin floundering on the third ascent of Saturday's penultimate stage to surge into the lead ahead of Sunday's ceremonial ride into Madrid. Barring a crash on the 21st and final stage, Italian Aru (Astana), who is one minute and 17 seconds ahead of second-placed Joaquim Rodriguez of Spain (Katusha), is poised to go one better than his second-placed finish behind Alberto Contador at this year's Giro d'Italia. Poland's Rafal Majka (Tinkoff-Saxo) is third overall, 12 seconds behind Rodriguez, with Colombian Movistar rider Nairo Quintana a further 33 seconds back in fourth. "This victory is thanks to my team mates, it's not just about me," Aru told reporters after pulling on the leader's red jersey. "They've been phenomenal for the whole Vuelta." Saturday's thrilling denouement was bitter for Dutchman Dumoulin (Giant-Alpecin), who claimed the leader's red jersey with a scorching time trial on Wednesday and led Aru by a slender six seconds overnight. The 24-year-old from Maastricht dropped down to sixth overall, nearly four minutes adrift of the Sardinian, and will miss out on a podium finish. Dumoulin managed to stay with Aru until the Morcuera ascent, the third of four climbs on the 176-km slog between San Lorenzo de El Escorial and Cercedilla. Once the Italian's Astana teammate Mikel Landa started to force the pace, however, Dumoulin's challenge quickly faded and he never looked like coming back once he was dropped. "Tomorrow I will be proud but today it's just disappointment," he said. "I was just empty, I had no legs," he added. "I had an idea that was the case but I just fought for all I was worth and in the end you just got to deal with it." Ruben Plaza (Lampre-Merida) rode alone at the front of the field for more than 100 kilometres of Saturday's stage and crossed the line just over a minute ahead of Jose Goncalves (Caja Rural) in second and Alessandro De Marchi (BMC) in third. — Reuters