Gouegard was part of a 24-man breakaway that built up an unassailable lead over the peloton before attacking 22km from the line to take the 185.8km stage from Medina del Campo to Avila ahead Portugal’s Nelson Oliveira and Belgian Maxime Monfort in a time of 4hr 19min 20sec.
The leading contenders were still 15km from the line when Gouegard finished, but Dumoulin managed to eek out another three seconds on Aru in the final kilometre to add to his three-second overnight lead.
Aru will have his chance to overcome the Giant-Alpecin rider on Saturday’s penultimate stage that contains four category one climbs likely to favour the Italian, who is the more accomplished climber.
“These are hard days and everyone is attacking me. I feel good, there is always stress but I can handle it otherwise I wouldn’t be in red today,” Dumoulin told Television Espanola.
“It is going to be a very exciting day tomorrow. Anything can happen, but I am staying positive.”
Aru is aiming to go one better than his second place finish at the Giro d’Italia earlier this year, but was lucky to escape unharmed after suffering a small crash midway through the stage.
The Astana rider quickly caught back up with the peloton, but unlike on Thursday when Dumoulin had to neutralise a series of attacks, Aru didn’t try to distance himself from the 24-year-old.
And it was Dumoulin who finished the stronger through a cobbled final kilometre to slightly increase his lead.
The 175.8km stage on Saturday takes the riders from San Lorenzo de El Escorial to Cercedilla before the race finishes with a parade around the centre of Madrid on Sunday. – Agence France-Presse