Emma Raducanu retired from her first-round match with Bianca Andreescu at the Internazionali d'Italia because of a lower back injury.
The world number 12 was trailing 6-2 2-1 when calling time on the match against Andreescu in a highly anticipated showdown between two of the past three US Open winners.
Raducanu initially left the court for treatment ahead of the seventh game of the opening set for a medical timeout and completed just four more games.
Speaking after her withdrawal, coming two weeks before the French Open, Raducanu explained she did not want to aggravate an injury sustained at last week's Madrid Open.
"I thought maybe taking one, two days off, it would go away because a lot of the other small niggles I've had, they've kind of gone away after taking, like, two days off," she said.
"Then I got here and I was training, but it just didn't seem to get better. I was training with some limitations. I wasn't moving really.
"I was just playing where I knew where the ball was coming, just staying in one corner. I think I must have underestimated the unpredictability of competition in a match.
"The last few weeks have been really positive. I've learned a lot about myself and my game has definitely improved on this surface but I need to make sure my back is fully right.
"I need to just keep on it. I don't want to play my next match with a feeling of limitation because I think that I learned my lesson from this week, when to push, when not to push."
Ons Jabeur joined Andreescu in the last 32 with a 6-0 7-6 (7-1) victory over Sorana Cirstea to keep her impressive run of form going.
The Tunisian won her first WTA 1000 title in Madrid last week and has now won seven successive main draw matches for the first time in her career
Elsewhere in Tuesday's action, American qualifier Lauren Davis pulled off a shock 6-2 6-3 win against number 11 seed Jelena Ostapenko.
Fellow Americans Jessica Pegula, Madison Brengle and Amanda Anisimova also advanced, beating Liudmila Samsonova, Marta Kostyuk and Tereza Martincova respectively.
Anisimova, who is now the player with the most wins in three sets so far in 2022 with nine, will face Belinda Bencic for a place in the last 16.
Djokovic withdraws from ATP Finals
Novak Djokovic has pulled out of the ATP Finals, which start in Turin later this week.
Djokovic pulled out of the Paris Masters last month, and the world number five will now not feature in the season-ending tournament.
The 37-year-old, who lost to Jannik Sinner in the Shanghai Masters in his last competitive appearance, is sat on 99 ATP Tour-level titles, and his wait for a 100th victory will now roll into 2025.
Djokovic confirmed on Tuesday that he would not be participating in the ATP Finals.
"I was really looking forward to being there, but due to ongoing injury I won't be playing next week," Djokovic said on social media.
"Apologies to those who were planning to see me. Wishing all the players a great tournament. See you soon!"
Jannik Sinner, Alexander Zverev, Carlos Alcaraz, Daniil Medvedev and Taylor Fritz have all qualified for the tournament.
Andrey Rublev, Casper Ruud and Alex de Minaur are the three players contesting for the remaining two spots.
WTA Finals: Sabalenka digs deep to reach semi-finals
Aryna Sabalenka became the first player to book her place in the WTA Finals semi-finals after her straight-sets win over Jasmine Paolini on Monday.
The Belarusian had to dig deep in the second set but prevailed in 91 minutes, beating the Italian 6-3 7-5 in Riyadh to secure top spot in the Purple Group after two games.
While Sabalenka cruised through the first set, she was almost forced to a decider, but saved two set points in the 10th game of the second to level the score at 5-5 before going on to claim the victory.
In doing so, she became the first player to reach back-to-back semi-finals at the tournament as world number one since Serena Williams in 2013-14.
Having won three of her previous four tournaments and won 22 of her 23 matches in that time, Sabalenka is now just one win away from securing the year-end world number one spot for the first time, a feat she can achieve if she beats Elena Rybakina on Wednesday in the final round-robin match.
And she can go into it with confidence after improving her record against top-five opponents in 2024, with this her fifth such triumph.
"I'm proud of myself. Not only myself, my team," Sabalenka said.
"We were able to overcome a lot of things. To be able to show such great tennis and become World No. 1. It's teamwork. It's not only me. The behind-the-scenes work nobody sees.
"But they do a lot for me. I really appreciate them for everything they do for me. This is motivation for me to keep winning on this court. Those guys deserve to be called the best team ever."
In Monday's other match, Zheng Qinwen kept her hopes of reaching the final four alive with her win over Rybakina.
The Olympic champion was forced to go the distance though, despite getting the first break in the first and second sets, but eventually came out on top 7-6 (7-4) 3-6 6-1 in just under two-and-a-half hours.
Since the event's inauguration in 1972, Zheng is just the second Chinese player to win a match at the WTA Finals after Li Na.
It was a milestone victory for the 22-year-old as well as she earned her 50th win of 2024, improving her record to 50-17, making her the first Chinese player in the Open Era to hit that mark in a calendar year, though she acknowledged she could have made things easier for herself.
"I was the one to make the first break, and then I let her back in the first," Zheng said.
"Then it happened again in the second. But in the third set, I talked to myself. I broke her first and I stayed focused.
"Finally, in the third set, I start to play my tennis again. So, I'm really happy to win the match."
WTA Finals: Swiatek battles from the brink to make winning start
Iga Swiatek began her bid to regain the world number one ranking by recovering from a set and double break down to beat Barbora Krejcikova in her first match at the WTA Finals.
Swiatek, playing in her first competitive game since her US Open quarter-final exit, emerged a 4-6 7-5 6-2 victor against the Wimbledon champion in Riyadh.
The Pole is the third player in the last 30 years to achieve three or more seasons in a row with over 60 wins, after Martina Hingis (1997-2001) and Caroline Wozniacki (2009-2011).
Only Elina Svitolina (12) has played fewer matches at the WTA Finals than Swiatek (13) to achieve 10 wins at this event since the reintroduction of the Round Robin format in 2003.
But the Pole acknowledged the difficulties she faced against Krejcikova, saying she must improve if she is to retain her WTA Finals crown.
“Even though I played a lot of those [practice] matches,” Swiatek said afterward. “I kind of forgot for a while how it is to feel all those things, a bit different stress and emotions.
"For sure, I needed some time to adapt. The most important thing was that even though it happened, I managed to fight through that. And was patient enough to wait to get better.”
In Sunday's other match, Coco Gauff beat fellow American and doubles partner Jessica Pegula 6-3 6-2 in the second Orange Group match.
Gauff moved to a win-loss record of 51-16 in 2024, including the Olympics and team events, equalling her career-high from 2023 for WTA-level match wins in a calendar year.
She is now only the fifth player to claim 20 or more WTA top 10 wins before turning 21, along with Kim Clijsters (45), Maria Sharapova (39), Ana Ivanovic (26) and Wozniacki (23) since 2000.
"I think maybe I served better than previous times and this is our first time, I think, playing each other on indoor hard, so maybe that had something to do with it," Gauff said.
"I don't know. I think I know I've lost to her a lot, but it doesn't feel like it sometimes.
"Because we do practice a lot, and obviously, when we're playing sometimes I win practice sets, sometimes she does. So it doesn't feel like the head to head is as bad as it was."
SportsMax is the Caribbean sports channel of choice, committed to providing sporting content of the highest quality to the Caribbean, delivered by a team of highly innovative, passionate and qualified professionals.
(876) 619-7629
digitalmedia@sportsmax.tv
