Etixx - Quick-Step rider Tony Martin, who won a road stage of Vuelta Ciclista al Pais Vasco solo in 2014, tried his luck again in 2015 by entering the breakaway at 162.2km Stage 4, but the four-rider breakaway was down to just Martin and Tom Danielson (Cannondale-Garmin) heading into the final kilometers with an advantage fluctuating between 10 and 18 seconds until they were finally caught with 6.8km to go.

Michal Kwiatkowski had been protected by his teammates going into the Usartza, with Michal Golas being the last rider to guide him into the climb. However, a three-rider attack consisting of Ion Izagirre (Movistar), Ilnur Zakarin (Katusha), and LL Sanchez (Astana) led to a high pace in what was left of the select group chasing them on the key climb. Eventually Zakarin was solo, and Sergio Henao (Team Sky) bridged to him with 3.4km to go. Kwiatkowski was unable to maintain contact with the select group behind the duo at about that point.

The group then headed into the last 2.2km of descending, and the duo was caught with 1.7km to go. Only 12 riders maintained in contention for the stage. Joaquim Rodriguez (Katusha) won, with Bauke Mollema (Trek Factory Racing) 2nd and Simon Yates (Orica-GreenEDGE) 3rd. Kwiatkowski crossed 23" down on the group in 13th place.

Carlos Verona crashed on the downhill on the first of two Category 1 climbs in the stage.  He has scratches on the left side of his body, but he finished the race. The team will closely monitor the situation and any further information will be provided in the next days.

Etixx - Quick-Step looks next to Stage 5 from Eibar to Aia, which is 155.5km in total distance. The penultimate stage, includes a final lap along the parcours of the ITT the next day. This stage includes nine categorized climbs and also the key point of a Category 2 finishing climb. This 1.5km ascent includes ramps between 12 and 17 percent, with the 17 percent being the last portion of the climb.