Serena Williams endured another rough day on her unofficial farewell tour, losing 6-4, 6-0 to 10th-seeded Emma Raducanu of Great Britain on Tuesday in the first round of the Western & Southern Open at Mason, Ohio.
Williams, 40, recently stated that she is nearing the end of her playing career as she plans to have a second child. The Cincinnati-area event was her third of the year: She lost in the first round at Wimbledon in late June and fell in the second round at Toronto last week.
Raducanu, 19, is also enduring a rough season. The reigning U.S. Open champion lost in the second round of all three of this year's majors to date, and her two best results were quarterfinal losses in Stuttgart, Germany, and Washington.
Raducanu needed just 65 minutes to rout Williams, committing just one unforced error in the match.
In her postmatch interview, Raducanu said of Williams, "I think we all need to just honor Serena and her amazing career.
"I'm so grateful for the experience of being able to play her and for our careers to cross over. Everything that she's achieved is so inspirational and it was a true honor to share the court with her."
Next up for Raducanu is a matchup against another former world No. 1 player, Belarus' Victoria Azarenka.
In other Tuesday action, 11th-seeded Coco Gauff withdrew during her first-round match against the Czech Republic's Marie Bouzkova due to a left ankle injury sustained during the opening set. Bouzkova led 7-5, 1-0 when Gauff stopped the contest.
Gauff, 18, was in front 5-3 in the first set when she tumbled to the court and injured her lower leg. She lost the next three games before being examined by a trainer.
Bouzkova then finished off the set and won the opening game of the second set before Gauff called it a day.
It was a difficult development for Gauff, who lost in the quarterfinals in each of her previous two events. She also reached the French Open final in the spring before losing to Poland's Iga Swiatek, the top-ranked player in the world.
Gauff is playing doubles with Jessica Pegula in the tournament and there was no immediate word on whether she would continue. There also is the matter of the U.S. Open being less than two weeks away.
Bouzkova faces Alison Riske-Amritraj in the second round.
Meanwhile, Japan's Naomi Osaka also went down in the first round as China's Zhang Shuai outplayed her and won 6-4, 7-5 in just 75 minutes.
Osaka held a 10-4 edge in aces but won just 37.1 percent of her second-serve points in the disappointing setback. Osaka committed 29 unforced errors and had 21 winners.
Zhang, who has four aces, will face Russian Ekaterina Alexandrova in the second round.
Romania's Sorana Cirstea also registered an upset, beating 12th-seeded Swiss Belinda Bencic 6-2, 6-7 (3), 6-4. Cirstea had eight aces and saved five of seven break points during a match that took two hours and 38 minutes.
Czech Karolina Pliskova, seeded 14th, recorded a 7-5, 6-1 victory over Venus Williams. Pliskova had an 8-2 edge in aces.
"I think I finally got it to a better level," Pliskova said. "Hard court is my favorite. I always do well in America, so hoping for more matches here."
Pliskova will next face Belgium's Elise Mertens, who notched a 6-1, 6-1 win over Ukraine's Anhelina Kalinina.
Also, Shelby Rogers hammered out nine aces while thrashing fellow American Sofia Kenin 6-1, 6-2 in just 66 minutes.
In other matches, Russia's Anna Kalinskaya beat Italy's Martina Trevisan 7-6 (2), 7-5, and Ukraine's Marta Kostyuk outlasted Italy's Camila Giorgi 6-4, 5-7, 6-4. Latvia's Jelena Ostapenko, the 16th seed, beat Brazil's Beatriz Haddad Maia, a finalist in Toronto last week, 6-4, 6-4.
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