The US national champion and 2016 WorldTour winner played off an attack by teammate and Olympic champion Anna van der Breggen to take the first race leader's jersey, with the Dutch rider sailing in for second.
Guarnier's team rode hard from early in the race to keep the peloton under control and set up Guarnier for the win. Hagens Berman-Supermint, Cylance, Visit Dallas-DNA and Team TIBCO were consistently active throughout the race with a non-stop series of attacks and counterattacks. The most successful attack of the day came from Lizzie Williams (Hagens Berman-Supermint) who gained over a minute on the peloton midway through the race. Williams countered as Boels Dolmans brought back another breakaway attempt and was able to establish a quick separation from the field.
Karol-Ann Canuel began the fireworks with an attack on the final climb achieving a small gap, which was quickly neutralised by UnitedHealthcare. Anna van der Breggen then jumped taking Guarnier along with her. Guarnier launched her effort with 300 meters to go winning the race with teammate Van der Breggen four seconds behind.
"I think tomorrow we are in a really good situation as a team," Guarnier said about her team's control of the general classification. "I think that with Anna in second right now, and we have really strong climbers, we should be in a good situation and hope to continue with our success here."
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