In-form Spanish veteran Alejandro Valverde scorched into the overall lead by claiming the fifth stage of the Tour of the Basque country on Friday.
Valverde, 36, claimed his sixth stage win of the season to go with overall victories in the Tour of Andalucia and Tour of Catalonia by edging out France's Romain Bardet and Colombian Rigoberto Uran in a time of 3hrs 26mins 32secs over the 139.8km run from Bilbao to Eibar.
A 27.7km individual time-trial around Eibar will decide the winner in Saturday's final stage.
Victory means Valverde takes over the leader's yellow jersey, but he is tied with Bardet, Uran, Louis Meintjes and Michael Woods on the same time in the overall standings.
"We have a great opportunity, but whatever happens I will be happy," said Valverde.
"This year I have eight victories, two tours and now I'm leading in the Tour of the Basque country, so no matter how it goes I will be happy."
Four-time champion Alberto Contador was three seconds back in sixth on the day and in the overall standings.
Overnight leader David de la Cruz lost 22 seconds back in 10th to slip to ninth overall.