Qualifier Anna-Lena Friedsam overcame No.1 seed Emma Raducanu 7-5, 0-6, 6-3 in 2 hours and 21 minutes to reach the WTA Zavarovalnica Sava Portoroz quarterfinals.

The result puts the 28-year-old into the last eight of a tour-level event for the first time since her runner-up showing at Lyon 2020. Prior to this week, Friedsam had won only one WTA main-draw match this season, and her ranking has slumped to No.213.

Friedsam had defeated Raducanu 6-4, 6-2 in their only previous meeting, in the 2019 Roehampton ITF W25 semifinals when the Briton was 16 years old. The rematch was a tighter and more unpredictable affair that featured several wild momentum shifts.

After three breaks in the first four games, Raducanu settled first, and moved out to a 5-3 lead. But four set points came and went, two on the Friedsam serve and two on her own -- three thanks to errant Raducanu backhands and one due to a dead net cord.

Serving at 5-6, Raducanu clutched her left leg and, with her movement visibly hampered, Friedsam took advantage to seal the first set with a dropshot. But Raducanu was rejuvenated after returning from a medical time-out with her leg strapped.

The opening three games of the second set were an electrifying series of seven total deuces. Most points were ended with clean winners from all corners of the court by both players, but a net-rushing Raducanu was able to win all three games and thereafter wrap up the set without losing a game.

Friedsam and Raducanu settled into a solid rhythm on serve in the decider, with no break points for either player through the first seven games. But it was the German who found an extra gear, capturing the crucial break for 5-3 with a fizzing return winner and then finding another clean backhand winner on her first match point.

Raducanu is the second Briton that Friedsam has beaten this week. The former World No.45 also took out Harriet Dart in the second round of qualifying. Friedsam has also managed to reach the last eight despite being bagelled twice: in her first-round match, she lost the first nine games against Elizabeth Mandlik before recovering for a 0-6, 6-4, 6-1 win.

Portoroz R2 highlights: Parry d. Potapova | Siniakova d. Burrage | Bogdan d. Zidansek | Tsurenko d. Alexandrova | Rybakina d. Martincova

Friedsam will next play Diane Parry, who moved into her third career quarterfinal after overturning a 5-1 first-set deficit to defeat No.9 seed Anastasia Potapova 7-6(2), 6-4. Katerina Siniakova, fresh off completing the Career Golden Slam in doubles at the US Open, was another winner, beating qualifier Jodie Burrage 7-5, 6-1.