Caroline Wozniacki and Naomi Osaka reach Pan Pacific final on Sunday

Caroline Wozniacki will take on Japanese teenager Naomi Osaka in the Pan Pacific Open final in Tokyo after the duo came through three-set semi-finals on Saturday

Former world No 1 Wozniacki beat defending champion Agnieszka Radwanska 4-6 7-5 6-4 in a two hour, 50 minute epic while Osaka bounced back after a poor first set to beat Elina Svitolina 1-6 6-3 6-2.

There were 13 breaks of serve in the topsy-turvy clash between Wozniacki and Radwanska, who served for the match in the second set.

However, she then lost five games in a row and Wozniacki eventually booked her place in a third Pan Pacific final when Radwanska netted - her 43rd unforced error of the match.

"I think every time I play her, we play really tough matches," said Wozniacki.

"I was lucky to win that second set and then we just fought really hard, both of us, in the third."

The 18-year-old Osaka got off to a sluggish start against world No 20 Svitolina and lost the first set amid a flurry of unforced errors.

But she then upped her game significantly and, helped by some powerful serving (seven aces in the match), she clinched a spot in her first ever WTA Tour final.

She becomes the first Japanese player to reach the Pan Pacific final since Kimiko Date-Krumm won the title in 1995.