Aranburu, who rides for Astana-Premier Tech, attacked 10 kilometres from the end of the 154.8km route from Zalla to Sestao and saw off his rivals to take victory.

The Spaniard led home a one-two for his team as compatriot Omar Fraile came second, while Tour de France champion Tadej Pogačar of UAE Team Emirates and Slovenia did enough for third.

Slovenia’s Primož Roglič, who won yesterday's time trial, leads Aranburu by five seconds on the overall standings after the Team Jumbo-Visma rider finished sixth.

Aranburu made full use of a combative race from those who are challenging for the general classification title as they battled it out on the final climb and descent.

The 25-year-old was able to hold off the chasing pack before crossing the line in a time of 3 hours 45min and 32sec, 15 seconds clear of team mate Fraile.

The International Cycling Union WorldTour race is due to continue with a 167.6km hilly stage from Amurrio to Ermualde tomorrow.