US Open champion Emma Raducanu ended her breakthrough season on Tuesday when she was knocked out of the WTA event in Linz, losing her second round match 6-1, 6-7 (0/7), 7-5 to world number 106 Wang Xinyu.

The 18-year-old top seed Raducanu, who confirmed after the match that Torben Beltz will be her new coach, stunned the tennis world in September when she became the first qualifier ever to win a major.

Playing in just her third tournament since her Flushing Meadows success, the British teenager, now ranked 20 in the world, struggled against the 20-year-old Chinese who galloped through the first set as Raducanu battled to keep her service together.

The Briton was far from her most fluent in the second set but made short work of Wang in the tie-break which she took to love as she won 10 points in a row.

Wang, however, stayed with her in the decider, breaking to go 5-4 up after which Raducanu took a medical time-out for treatment for a hip spasm.

She picked herself up to save two match points and level at 5-5 but again failed to hold, allowing Wang to take her second opportunity to serve out the match, closing it out after two hours and 36 minutes on court.

It marked another disappointing day at the office for Raducanu who has been without a coach since parting company with Andrew Richardson shortly after her triumph in New York.

Raducanu, however, confirmed British media reports that Beltz, 44, who previously coached former world number one Angelique Kerber during her successful 2016 Australian Open and 2016 US Open campaigns, will take over for next season.

“I’m definitely very excited to work with him throughout the pre-season and into next year,” said Raducanu.

“I’m feeling excited about all the work that is to come.

“I think he brings a lot of experience. Obviously he’s worked with Kerber, who’s such a great player and has done extremely well, won three slams.

“I think that experience definitely helps with someone as inexperienced as me. He can help guide me through.”

Wang now faces American eighth seed Alison Riske in the quarter-finals after her 6-4, 6-4 win over Alize Cornet.

Second seed Simona Halep, who missed this year’s French Open and Wimbledon due to a left calf tear, eased into the last eight with a 7-5, 6-3 win over Aliaksandra Sasnovich.