Lulu Sun reached the second round at Eastbourne after stunning top seed Daria Kasatkina across three sets on Monday.
Kasatkina, who was also the defending champion at the tournament, succumbed to the blustery conditions as she was beaten 5-7 6-2 3-6 in two hours and 10 minutes.
Sun had raced into a 4-0 lead in the opening set before Kasatkina reeled off the next five games to storm ahead, but the New Zealander quickly regained control.
She took the opening set after winning three games on the bounce, but Kasatkina roared back by going 4-2 up in the second before serving out to level the contest.
But it was Sun who emerged victorious, with a break in the second game of the deciding set proving crucial to the outcome of the match.
The world number 46 sealed her progression with a fierce forehand that Kasatkina returned long, with Sun now facing Anna Blinkova, who beat Marie Bouskova, next.
Data Debrief: Sun shines bright before Wimbledon return
Sun catapulted herself into the limelight with her quarter-final run at Wimbledon last year, and she put on another fine display in her preparations for the grass-court major.
She won 63% (34/54) of her first-serve points while also serving up four aces to Kasatkina's two, but was only able to save two of the seven break points she faced.
Sun arrived in Eastbourne with a 6-15 record in 2025, but will be hoping she can put together a solid run at the tournament before returning to the All England Club.
