Agnieszka Radwanska fended off a challenge from teenage giant-killer Belinda Bencic Sunday to win the WTA Pan Pacific Open, a victory that will propel the Pole back into the world's top 10.

The seventh-seed grabbed her first tournament victory of this year, and her 15th career title, with a dominant 6-2, 6-2 victory against the eighth-seed Swiss.

Radwanska, who will move up five places to eighth when the new rankings are released on Monday, said she hoped to use the rest of the season to secure her place among the  elite top eight who will compete in the season-ending WTA finals in Singapore.

"I am so so happy that I could play my best tennis today," said Radwanska, who won in Tokyo in 2011 and was runner-up in 2012.

"Belinda really pushed me to play 200 percent today," she said.

Radwanska repeatedly nailed accurate serves to deep corners, mixing them with drop shots, lobs and passing shots to send Bencic running all over the court.