The peloton caught up with a quartet of riders within the final two kilometres of the lumpy final stage of the Tour of California before Balsamo came around the outside of a strong Hagens Berman Supermint leadout to take a deserved win ahead of Arlenis Sierra (Astana) and Leigh Ann Ganzar (Hagens Berman Supermint).
An aggressive day in the saddle saw Anna van der Breggen (Boels Dolmans) once again take it upon herself to put pressure on the rest of the race, again attacking to put the field in difficulty with the early breakaway including Australian Brodie Chapman (TIBCO-SVB) potentially threatening her overall lead.
Another break formed soon after with again van der Breggen taking the chasing upon her own shoulders to bring the race back together with 46 kilometres left to race.
An attack of Pauliena Rooijakkers (CCC-Liv) and Kathrin Hammes (WNT-Rotor) got some traction and was later joined by perennial attacker Olga Zabelinskaya (Cogeas Mettler) and Marta Cavalli (Valcar Cylance).
The escapees were dragged back within the final two kilometres, with Balsamo taking out the sprint in convincing fashion.
Stage 1 winner van der Breggen finished safely in the main bunch and secured the yellow jersey for the overall victory.