Venus Williams loses to Jelena Ostapenko at Birmingham Classic after injury concern

WATCH: Jelena Ostapenko defeats Venus Williams in the 2023 Rothesay Classic second round

BIRMINGHAM, England (AP) — Venus Williams couldn't cause an even bigger surprise at the Birmingham Classic.

The 43-year-old American, now ranked No. 697, lost 6-3, 5-7, 6-3 to second-seeded Jelena Ostapenko on Thursday in the second round of the grass-court tournament that is serving as a warmup for Wimbledon.

On Monday, Williams defeated 48th-ranked Camila Giorgi for a first victory over a player in the top 50 in nearly four years. She has just returned after six months out with a hamstring injury sustained in Auckland in the first week of the year.

Williams, who played with strapping around her right knee against Ostapenko, received an off-court medical timeout when at 2-2 in the second set. She looked uncomfortable when she returned to the grass but continued to play, fighting for every point and even saving a match point at 5-3 before recovering to win four games in a row and take it to a decider.

By the end of a 44-minute third set, Williams' mobility was limited and Ostapenko sealed victory with a forehand down the line.

A seven-time Grand Slam champion and five-time winner of the Wimbledon singles, Williams was this week granted a wild card by the All England Club for this year's championships and she has justified it.

Top-seeded Barbora Krejcikova earlier maintained her confident progress by reaching the quarterfinals with a straight-set win over fellow Czech player Tereza Martincova.

With the 6-4, 6-4 victory, Krejcikova has yet to drop a set at the tournament.

The No. 12-ranked Krejcikova won her first-round match 6-3, 6-3 against Cristina Bucsa.

Eighth-seeded Sorana Cirstea of Romania was beaten 6-3, 6-7 (1), 6-4 by Magdalena Frech of Poland, and Rebecca Marino of Canada defeated 150th-ranked American player Emina Bektas 6-4, 4-6, 7-6 (1).