Julia Boserup outlasted Sara Errani 6-7 (5-7), 6-4, 6-3 in a nearly three-hour duel on Monday to headline the opening day of the Hawaii Open at Patsy T. Mink Central Oahu Regional Park.

Boserup, a 26-year-old from California, lost the final three points of a tiebreaker to drop the 68-minute opening set to Errani, who peaked at No. 5 in the world in 2013 and won a career grand slam in doubles.

Boserup bounced back to force a decisive third set and the players were tied 3-3 when play was delayed by rain. Boserup won the final three games coming out of the break to advance to the second round of the WTA 125K Series event.

Earlier in the day, Ajla Tomljanovic of Croatia delivered the first upset of the tournament by knocking off fourth-seeded Kurumi Nara of Japan, 6-2, 6-2. American Allie Kiick advanced with a 7-5, 6-4 win over eighth-seeded XinyunHan of China.

The first round continues today at 10 a.m. with top-seeded Shuai Zhang of China, ranked 36th in the world, scheduled to face American Taysia Rogers in the second match of the day on CORP’s Center Court.