WATCH: Venus Williams defeats Camila Giorgi in the 2023 Birmingham first round

BIRMINGHAM, England (AP) — At age 43 and ranked No. 697, Venus Williams isn't done quite yet—especially on her favored surface of grass.

Williams upset 48th-ranked Camile Giorgi 7-6 (5), 4-6, 7-6 (6) after more than three hours at the Birmingham Classic on Monday for her first victory over a player in the top 50 in nearly four years.

Williams, a seven-time Grand Slam champion and five-time winner of the Wimbledon singles, was out for six months because of a hamstring injury sustained in Auckland in the first week of the year.

On her return last week, she lost to 17-year-old Celine Naef in the first round of the Libema Open in the Netherlands.

Williams said it was "touch and go" against Giorgi.

"There were so many moments where I thought, ‘This match is over,' then she would hit a shot from out of nowhere," Williams said. "She pushed me to be better than what I thought I could be, and it's great for me.

"I haven't played a lot of matches, and it's great to come through."

There were also wins for third-seeded Magda Linette, fifth-seeded Anhelina Kalinina of Ukraine and Bernarda Pera of the United States in the Wimbledon warmup event.