Tokyo: Caroline Wozniacki outlasted Agnieszka Radwanska 4-6, 7-5, 6-4 in a dog fight of a semifinal at the Pan Pacific Open on Saturday to end the Pole's reign at the Ariake Coliseum. The former world No. 1 prevailed in two hours and 50 minutes of hard-fought tennis and will meet Naomi Osaka in Sunday's final after the local wildcard rallied to secure a 1-6, 6-3, 6-2 over Ukraine's Elina Svitolina in the second semifinal. World No. 4 Radwanska served for the match in the second set but then lost five straight games as Wozniacki levelled up the contest and took an early break in the decider. There were 13 breaks of serve in the topsy-turvy encounter, however, and it was not until a fourth match point, which Radwanska slapped into the net for her 43rd unforced error, that the Dane was certain of her place in the final. "I think every time I play her we play really tough matches," Wozniacki said in a courtside interview. "She played really well today and I was lucky to win that second set and then we just fought really hard, both of us, in the third." Languishing at 28th in the world rankings after a string of injuries, Wozniacki reached the semifinal of the U.S. Open earlier this month and should be confident of clinching her second title in her third Pan Pacific Open final on Sunday. The 18-year-old Osaka got off to a sluggish start in her one hour and 47 minute contest against Svitolina, with the promising youngster lacking patience and committing a string of unforced errors in a disastrous first set showing. However, the home favourite regained her composure in the second set as her much improved service game, which included four aces, roused the crowd and she utilised her power to send the contest into a deciding set. Osaka continued to build on her momentum in the third, breaking the Ukrainian twice on her way to knocking out the world No. 20 as she reached her first Pan Pacific Open final. Sunday's contest will be the first meeting between Wozniacki and Osaka.