Wild card Bianca Andreescu advanced to the quarterfinals of the Toray Pan Pacific Open Tennis 2024 after No.2 seed Beatriz Haddad Maia was forced to retire trailing 3-0 in the first set due to a left back injury.

Tokyo: Scores | Draws | Order of play

The former US Open champion moves into the last eight of a tournament at WTA 500 level or above for the first time since making the 2022 Rome quarterfinals. It is her second quarterfinal of 2024, following her run to the 's-Hertogenbosch final on grass in June. Andreescu will next face No.9 seed Katie Boulter.

Haddad Maia was in visible discomfort from the second game of the match. After serving two double faults, she winced as she left a makeable forehand go past her. Down two break points, she required a medical timeout, and was only able to play one more game.

Andreescu, 24, has been plagued by health issues for most of her career to date. A back injury sidelined her for nine months between August 2023 and May 2024, and Tokyo is just her second tournament since the US Open after she suffered a knee issue. The Canadian, now ranked No.159, empathized with Haddad Maia in her on-court interview.

"I've been in her position many times and it's the worst feeling ever," she said. "I really wish her a speedy recovery -- the season is very long and we're all dealing with stuff all the time, but I hope this doesn't bring her down."

Andreescu also explained how she had dealt with her own setbacks.

"There are many ways to cope with it," she said. "At first, it was very hard to accept, and that was the toughest part for me. Trying to stay positive and not giving up, because there were many moments when I wanted to. But I truly love this sport, so that was a motivation for me to keep going."

Elsewhere, Andreescu's compatriot Leylah Fernandez reached her fifth quarterfinal of the season after the No.8 seed edged Varvara Gracheva 6-0, 3-6, 7-5. No.6 seed Diana Shnaider raced past Viktoriya Tomova 6-2, 6-2, setting up a last-eight meeting with Sayaka Ishii, the 19-year-old Japanese qualifier. Ishii continued her breakthrough tournament by defeating fellow qualifier Zeynep Sonmez 4-6, 6-2, 6-3 to reach her first WTA quarterfinal in just her second main draw.

Japanese qualifier Ishii, 19, battles past Sonmez into Tokyo quarters