TOKYO, Sept. 25 (Xinhua) -- Venus Williams came back from a set down to dispatch of Romania's Simona Halep on Wednesday, booking her berth in the quarter-finals of the Pacific Pacific Open here.

Williams, having beaten top seed Victoria Azarenka on Tuesday, broke serve in the third set to beat the No. 13 seed Helep 4-6, 7-5, 6-3 at the Ariake Tennis Forest Park in Tokyo.

In the game that lasted just under two and a half hours, Williams, who ranks 63rd in the world following 2-years of illness, produced five aces in the match, which was a hard-fought battle with both players struggling to hold serve, with Williams winning seven break points to Halep's six.

Despite being at the top of the international circuit a decade ago, the 33-year-old American said that despite her battle with illness she has no plans on calling it a day.

"I'm not quite sure how I won the match as she was hitting the ball so hard. I've never seen her hit like that before," Williams told reporters after the match.

"In the end it was about who wanted it more and who was going to fight harder and have more belief and thankfully that person was me," Williams said, adding that she also wanted to stay in Japan longer and had no plans on retiring from the game.

Williams, who showed her experience on the big points against a feisty Halep, will now face Canada's Eugenie Bouchard, ranked 46th in the world, in the quarter-finals.