Top-seeded American Serena Williams was upset in the third round of the women’s singles tournament at the Olympics by Ukraine’s Elina Svitolina, 6–4, 6–3.
At one point in the second set, the defending Olympic gold medalist doubled faulted twice in a row, and appeared to be experiencing some discomfort in her injured shoulder which kept her out of the Rogers Cup in late July.
Williams had 37 unforced errors in the 19-game match, and just a 63% first-serve percentage.
Svitolina, the No. 15 seed in the women’s draw, got by Germany’s Andrea Petkovic in the first round, and Great Britain’s Heather Watson in the second. She will face No. 11 Petra Kvitova in the quarterfinals.