Vollering was part of a five-rider leading group which formed on the last of six classified climbs on the 117.9 kilometre second stage in Mallabia.

The SD Worx rider was joined in the group by Canada’s Olivia Baril, France’s Juliette Labous, Italy’s Marta Cavalli and Pauliena Rooijakkers of the Netherlands.

Vollering’s SD Worx team were able to slow the chasing group, allowing the breakaway to remain clear to the finish.

The uphill sprint finish saw Vollering pull clear of her rivals to cross the line in a winning time of 3hrs 16mins 8secs.

She finished with a two second cushion over runner-up Baril, riding for Valcar Travel and Service, with Cavalli of FDJ Nouvelle-Aquitaine Futuroscope third on the same time.

Rooijakkers, who finished as the runner-up on yesterday’s stage, and Labous ended four seconds behind the winner.

The chasing group ended 17 seconds adrift.

The result extends Vollering’s advantage in the general classification.

She will take a 22 second cushion into tomorrow’s final stage over Rooijakkers.

United States’ Kristen Faulkner is third at 42 seconds down, with Cavalli fourth at one minute behind.

The inaugural women’s race is due to conclude with a 139.8km stage in Donostia-San Sebastián.

The stage is scheduled to be a repeat of last year’s women’s Clasica San Sebastian.

The three-stage race, which is part of the International Cycling Union (UCI) Women’s WorldTour circuit, is the women’s equivalent of the men’s Tour of the Basque Country.

Organisers issued an apology yesterday after the race director implied on radio that they had "almost been forced to organise it" as a "matter of fashion."