Sloane Stephens was upset in the first round of Wimbledon for a second straight year, this time falling 6-1, 6-3 to Donna Vekic of Croatia on the opening day of main-draw play.
Stephens, the 2017 U.S. Open champion and French Open runner-up a month ago, dropped to 10-7 all-time at Wimbledon, where she has experienced the least success of the four Grand Slams.
Later, Serena Williams beat 105th-ranked Dutchwoman Arantxa Rus 7-5, 6-3 in her first grass-court match in two years. Williams, a six-time Wimbledon champion, is playing for the first time since withdrawing during the French Open with a pectoral muscle injury.