Andrea Petkovic advances to the next round of Bank of the West Classic

Stanford (USA): Germany’s Andrea Petkovic reached the second round of the Bank of the West Classic with a 6-1, 6-4 win over Croatia’s Alja Tomljanovic on Monday and also benefited from the elimination of an experienced potential opponent in the next round.

Petkovic dropped serve twice but produced six breaks of her own as Tomljanovic struggled on serve, getting less than half her first serves into play.
Petkovic, whose career has been interrupted by knee injuries, will next face 16-year-old qualifier Naomi Osaka of Japan, who defeated former U.S. Open champion Samantha Stosur 4-6, 7-5 (7), 7-5.

Teenage qualifier Osaka dealt a telling blow to the former U.S. Open champion’s preparations for this year’s Grand Slam at Flushing Meadows.
Osaka, 16, dropped serve for the first time to lose the first set, then rallied for a 5-3 lead in the second before winning three straight points to claim the tiebreaker.

Stosur took a 5-3 lead in the third set, but Osaka went on a roll to win the last four games and finish off the match in two-and-a-half hours.Karolina Pliskova of the Czech Republic beat Japanese veteran Kimiko Date-Krumm 6-1, 6-3 to set up a second-round match against top-seeded Serena Williams, who had a bye through the first round in her comeback tournament following an illness that ended her run at Wimbledon.

In other first-round matches, American qualifier Sachia Vickery defeated China’s Shuai Zhang, 6-1, 6-2 and Varvarel Lepchenko beat Caroline Garcia of France 6-4, 6-3.