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Oct 25 (Reuters) - Ecuadorian rider Richard Carapaz earned the leader's red jersey after a thrilling summit finish on the notorious Formigal mountain in stage six of the Vuelta a Espana on Sunday as Primoz Roglic slid down from first to fourth overall.
Spaniard Ion Izagirre of Astana won the stage by 25 seconds with a brilliant solo performance but the real drama took place further back, with Carapaz finishing strongest of the overall favourites to cross the finish line 55 seconds behind in 12th.
Slovenian Roglic, who suffered a mechanical problem inside the final 30 kilometres as the pouring rain intensified, came in one minute 38 seconds behind in 20th to surrender his lead to 2019 Giro champion Carapaz.
Carapaz holds an 18-second lead over second-placed Briton Hugh John Carthy, with Irishman Dan Martin 20 seconds down in third.
Roglic, who surrendered the leader's yellow jersey on the final day of the Tour de France in September, is 30 seconds back in fourth.
The stage was supposed to finish at the Tourmalet summit in the French section of the Pyrenees mountain range but new coronavirus restrictions in France forced organisers to totally redesign the stage with only two days' notice.
The stage instead ended at the category-one Formigal after passing through the Picos de Infierno, which translates as the Peaks of Hell, featuring more than 26 kms of uphill terrain to the finish.
It was on the Formigal that Nairo Quintana laid waste to Chris Froome in the 2016 Vuelta and increased his lead over the Briton by nearly three minutes on his way to winning the title.
Monday is the first rest day of the Vuelta, which has been trimmed down from 21 stages to 18 due to the coronavirus pandemic disrupting the cycling calendar. (Writing by Julien Pretot; Editing by Clare Fallon)