Theresa Cliff-Ryan won the first stage of the Exergy Tour on Friday, beating out German sprinter Ina Yoko Teutenberg.
Cliff-Ryan covered the rainy 76.7-mile stage, which wound through the countryside near southern Idaho's Snake River, in 3 hours, 16 minutes.
Australian Rochelle Gilmore was third.
Teutenberg, a German Olympian from 2000 hoping to compete in the London Games this summer, takes the five-day race's overall lead.
Cliff-Ryan rides for the Exergy 2012 team and is a teammate of U.S. gold medalist Kristin Armstrong, a Boise-based rider who crashed Thursday evening and broke her collarbone. Armstrong had surgery Friday, but arrived in Nampa in time to see Cliff-Ryan win.
Italian world champion Giorgia Bronzini fell near the finish Friday, but suffered only minor injuries. Bronzini is coming off a shoulder injury.