Top-seeded Caroline Wozniacki withdrew from the Citi Open in Washington on Tuesday due to a right leg injury, shortly before she was scheduled to play her opening match.
The 28-year-old Danish player said the ailment cropped up in practice Monday.
“It’s just something that has been nagging for a little while,” Wozniacki said. “Hopefully it will be fine.”
Wozniacki, who is ranked second in the world, won the Australian Open in January for her first major championship in 43 events. This summer, she lost in the fourth round at the French Open and the second round at Wimbledon.
Belgium’s Ysaline Bonaventure, a lucky loser from qualifying, entered the main draw in Wozniacki’s place and got a first-round matchup with Ukraine’s Anhelina Kalinina.
Second-seeded Sloane Stephens won an all-American first-round matchup Tuesday, beating Bethany Mattek-Sands 7-5, 6-4. Third-seeded Naomi Osaka of Japan defeated American Bernarda Pera 6-2, 7-6 (4).
Seventh-seeded Donna Vekic of Croatia knocked out American Caroline Dolehide 6-3-, 6-4, and eighth-seeded Yulia Putintseva of Kazakhstan topped Germany’s Tatjana Maria 6-3, 3-6, 6-4.
Sixth-seeded Belinda Bencic of Switzerland completed a rain-delayed 7-5, 6-2 win over Great Britain’s Harriet Dart. Also advancing were Japan’s Nao Hibino and Romania’s Ana Bogdan.
Mubadala Silicon Valley Classic
Belarus’ Vera Lapko pulled off a first-round upset, beating seventh-seeded Shuai Zhang of China 7-6 (2), 6-0 in San Jose, Calif.
Lapko came through at clutch moments, saving seven of the eight break points she faced.
Fifth-seeded Mihaela Buzarnescu of Romania beat American Sachia Vickery 6-3, 4-6, 6-3, and eighth-seeded Timea Babos of Hungary defeated France’s Kristina Mladenovic 6-4, 6-2. Heather Watson of Great Britain got past American Claire Liu 6-4, 3-6, 6-4.
American Serena Williams, the sixth seed, was scheduled to play Great Britain’s Johanna Konta on Tuesday night.
—Field Level Media