Cycling-Dumoulin fends off Aru to maintain Vuelta lead

MADRID, Sept 10 (Reuters) - Dutchman Tom Dumoulin comfortably held off a string of attacks from closest rival Fabio Aru to maintain his slender lead in the Tour of Spain after the 18th stage won by Irishman Nicolas Roche on Thursday. Aru (Astana) tried at least five times to drop Dumoulin (Giant-Alpecin) on the hilly 204-kilometre ride between Roa and Riaza but the 24-year-old from Maastricht stayed glued to the Italian's wheel before they crossed the line together. Roche (Team Sky) won the stage by outsprinting Spaniard Haimar Zubeldia (Trek), with Jose Goncalves of Portugal (Caja Rural) third and home rider Alejandro Valverde (Movistar) fourth. Dumoulin, who claimed the leader's red jersey with a scorching time trial on Wednesday, is three seconds ahead of second-placed Aru with three stages remaining including Sunday's ceremonial finish into Madrid. "There are hard days coming up but we've survived the first one and it was a good day," Dumoulin told reporters. "Aru tried very hard but I actually was never in trouble and after his first attack I knew I would keep the red jersey." Joaquim Rodriguez of Spain (Katusha) is more than a minute behind in third and Poland's Rafal Majka (Tinkoff-Saxo) nearly two and a half minutes adrift in fourth. The first Dutchman since Joop Zoetemelk at the 1980 Tour de France to lead a grand tour in the final week, Dumoulin is in a strong position to secure a debut triumph in one of cycling's premier races. Aru, however, who was second in this year's Giro d'Italia, will look to make his climbing ability count particularly on Saturday's mountainous 20th stage from San Lorenzo de El Escorial to Cercedilla. (Writing by Iain Rogers, editing by Tony Jimenez)