The day had started with one notable non-starter, as Shirin van Anrooij was ruled out through illness before the time trial. Ilaria Marinetto was the first rider down the start ramp, beginning a stage where the early kilometres were gentler before the road pitched up more sharply after the first intermediate checkpoint.
Solene Muller set the first serious target at the finish, before Urska Zigart produced the first major ride of the day. Zigart blew Muller’s benchmark away by around a minute, only for Reusser to respond with a much bigger statement.
Van der Breggen blows race apart
Reusser had started on a road bike and was not the quickest through the opening section, but her ride transformed once the gradients stiffened. The Swiss rider accelerated hard on the climb and finished in 32:42, moving 50 seconds ahead of Zigart and setting the first elite benchmark at the finish.
Monica Trinca Colonel came closest among the next wave, finishing 27 seconds slower than Reusser, while Zigart remained inside the top 10 after her strong climb. Vollering then appeared to be on course to challenge for the stage win after starting on a time trial bike and going faster than Reusser at the first split. The Dutch favourite faded later on the climb, however, crossing the line six seconds slower than Reusser.
Van der Breggen was already on another level. She flew through the first intermediate point 36 seconds faster than Vollering and carried that advantage all the way to the summit finish, where she moved well beyond the rest of the field.
Antonia Niedermaier finished fourth at 1:26, with Trinca Colonel fifth at 1:31. Lauren Dickson, Femke de Vries, defending champion Elisa Longo Borghini, Zigart and Isabella Holmgren completed the top 10.
Longo Borghini lost significant time to her main rivals, finishing 1:51 behind Van der Breggen. Her ride kept her in the wider GC picture, but left her chasing after the first serious climbing test of the Giro.
Balsamo’s opening reign in pink ended on the Nevegal slopes. After inheriting Stage 1 following Lorena Wiebes’ expulsion and then winning Stages 2 and 3 on the road, the Lidl - Trek sprinter finally gave way once the Giro reached GC terrain. Van der Breggen now leads the race heading into Stage 5, a 146km mountain stage from Longarone to Santo Stefano di Cadore. After one emphatic uphill time trial, the Giro d’Italia Women has a new leader and a very different shape.