Date Krumm, who turned 40 last month, broke third-seeded Israeli Peer to go up 6-5 in the third set before serving out for a 3-6, 7-6 (5), 7-5 win.

“Considering my age and the years I was away from the tour, I would say this is a miracle” Date Krumm said “I just hope that my physical and mental health will last one more game.” Date Krumm's opponent in the final will be another veteran — the 33-year-old Tamarine Tanasugarn of Thailand, who upset second-seeded Marion Bartoli of France 6-2, 7-5.

The oldest player to win a WTA singles title was Billie Jean King in Birmingham in 1983 when she was 39 years, 7 months and 23 days old.

Date Krumm and Tanasugarn are tied 1-1 in head-to-head.

The Japanese veteran has an 8-6 career record in finals while Tanasugarn is 3-7.

Date Krumm, who ended a 12-year retirement in April 2008, reached the third round of the Pan Pacific last month after beating defending champion Maria Sharapova and Daniela Hantuchova.