Three champions at Grand Slam or WTA 1000 level took to the court on Tuesday at the AUX Ningbo Open, but none survived their first-round contests.

Ningbo: Scores | Draws | Order of play

Marketa Vondrousova returned to action for the first time since a knee injury forced her to withdraw ahead of her US Open quarterfinal against Aryna Sabalenka, and was knocked out by fellow Czech Karolina Muchova 6-4, 6-3.

Victoria Mboko will have to wait another week to get back to winning ways after being overpowered by Dayana Yastremska 6-3, 7-6(3). The Ukrainian came from 5-2 down in the second set, meaning Mboko has now gone 0-4 since her shock title run in Montreal in August.

Finally, a physically ailing Emma Raducanu was defeated 3-6, 6-4, 6-1 by home favorite Zhu Lin. The former US Open champion required two medical time-outs during the match and was in visible discomfort throughout the third set.

Zhu hits stride as Raducanu fades

This time last year, former No. 31 Zhu was forced to miss the entire Chinese swing after an elbow injury sidelined her for six months.

“This year, I’m trying my best to perform,” she told the crowd in her on-court interview.

Currently ranked No. 219 and competing in Ningbo as a wild card, Zhu’s determination paid off as she scored her second Top 30 win since returning to action in January. The 31-year-old got off to an error-strewn start, but towards the end of the first set began to demonstrate how she could turn the contest around.

Zhu began extending both the rallies and the games, turning the match into a mentally and physically gruelling battle. The last four games of the first set all went to deuce, culminating in a riveting final game in which Raducanu saved three break points before converting her fifth set point with a forehand winner.

The Briton had won the battle, but Zhu laid the foundations for winning the war. She picked up where she left off in the second set, smothering Raducanu from the baseline with a series of cleanly-struck winners. Though Raducanu showed grit of her own to break Zhu back twice, the Chinese player never took her foot off the pedal and sealed the set with a third break of serve.

Raducanu had required a medical time-out trailing 4-3 in the second set, and her movement was visibly hampered as she took to the court for the decider. A second medical time-out down 2-1 did not help matters. On resumption, Zhu rattled through 16 of the last 19 points of the match as Raducanu’s resistance fell away.

Last week in Wuhan, Raducanu retired due to dizziness trailing Ann Li 6-1, 4-1 in the first round.

Zhu will next face No. 1 seed Mirra Andreeva — one of three players in the Ningbo draw still in contention for WTA Finals qualification. The pair met at the same stage of Beijing three weeks ago, with Andreeva winning 6-2, 6-2.

Yastremska snaps losing streak, Mboko’s goes on

Yastremska and Mboko came into Ningbo in similar positions. Both were on three-match losing streaks affected by health issues: Mboko sustained a wrist injury during her winning Montreal run, pulled out of Cincinnati, and on returning to action fell to Barbora Krejcikova at the US Open, Anastasia Potapova in Beijing and Ekaterina Alexandrova in Wuhan. Yastremska was also forced to withdraw from Cincinnati due to illness, then lost to Anastasia Pavlyuchenkova at the US Open and Jessica Bouzas Maneiro in Beijing before a neck injury caused her to retire against Laura Siegemund in Wuhan.

A patchy contest saw the pair combine for 16 double faults — nine for Yastremska and seven for Mboko — and 11 breaks of serve. Throughout, though, Yastremska displayed the greater firepower, and the Ukrainian largely dictated the tempo of proceedings. Both sets followed a similar pattern: a bright start and a break lead for Yastremska, who then lapsed into error to lose her advantage before regaining her accuracy.

In the second set, No. 30-ranked Yastremska was two points from being taken to a decider four times trailing 5-2, but she began hitting her spots just enough to avoid facing a set point. Upon coming through that game, Yastremska suddenly rediscovered her best level, racing through nine of the next 10 points, three games in a row and ultimately the match after a dominant tiebreak.

Yastremska will face another WTA Finals contender next, No. 3 seed Elena Rybakina. A win for Yastremska would seal Andreeva’s qualification for Riyadh.

Muchova pays tribute to Vondrousova after win

Muchova and Vondrousova aren’t just compatriots but friends and members of the same club back at home in Prague. When they landed in Ningbo, they paired up for their first practise — only to discover that the draw had pitted them against each other.

“I’ll talk for both of us that we didn’t like to see it,” Muchova said in her on-court interview.

Two players who have suffered more than their fair share of injuries, both Muchova and Vondrousova have been sidelined for several months of this season alone. Vondrousova, playing her first match in over a month, had fewer recent matches under her belt. Though she came up with some delightful passing shots early on, Muchova repeatedly caught her out with a barrage of inside-out forehand winners.

“I wish her the best,” Muchova said afterwards. “She’s been injured, so I had some advantage in matches and I used it. She’s such a greeat player and great competitor and so talented, so I’m happy I was able to finish in two sets.”

Muchova will next face No. 7 seed Diana Shnaider in an intriguing first-time encounter.