American qualifier Sachia Vickery started a new chapter in her professional tennis career Wednesday, reaching her first career WTA Tour quarterfinal, beating Puerto Rico's Monica Puig, 6-7 (4), 6-2, 6-1, in the Bank of the West Classic at Taube Family Tennis Center.
Serena Williams continues writing her own saga, turning the page on an odd withdrawal from Wimbledon with a 7-5, 6-2 victory over Czech Republic's Karolina Pliskova.
Vickery won two qualifying matches and then beat China's Shaui Zhang in straight sets on Monday.
"I haven't had the greatest year so far," Vickery said. "It's been good but I haven't reached my expectations yet. I think this win is definitely a confidence booster heading into the Open."
Vickery has played nine WTA Tour main draw matches, winning three of them. Her only previous WTA level tournament win came in the first round of last year's U.S. Open, her WTA debut.
"I've received a few wildcards before but had to earn those," Vickery said. "Qualifying is always great because you have two matches under your belt where the opponent probably hasn't played a tournament on the hard court in a long time."
Vickery has come a long way since making her professional debut in 2009, at age 14. She's never won a tournament at any level but has been ranked as high as sixth on the ITF circuit.
Beating a couple of higher-ranked players, producing her first two-match win streak on the WTA Tour, has helped her confidence.
"I think this match shows me that I can compete with the top girls," she said. "The courts here are really quick and it helped me today because I was taking the ball earlier and she might have been having some problems."
Vickery will meet Varvara Lepchenko, who earned her spot in the quarterfinals by beating second-seeded Angieszka Radwanska, 6-3, 3-6, 6-4.
Lepchenko beat the fifth-ranked Radwanska for the first time in six meetings in recording the best result of her career. Lepchenko beat a Top-10 player for just the third time in 24 matches.
Radwanska, the runner-up at last year's event, became the highest-seeded player to fall in the tournament.
Eighth-seeded Andrea Petkovic of Germany avoided an upset, beating 16-year-old qualifier Naomi Osaka of Japan, 6-2, 6-2.
Williams looked healthy and played sharp in her first competition since defaulting during a doubles match with her sister Venus at Wimbledon because of a viral illness.
The world's top-ranked player stopped worrying and started having fun again. Encouraged by a large crowd, Williams turned in a workman-like victory.
"I thought I played well," Williams said. "I'm on the right path, I'm excited and I'm looking forward to my next match."
Williams will meet the winner of Thursday's match between fifth-seeded, and former No. 1, Ana Ivanovic and qualifier Carol Zhao, a Stanford sophomore playing in her first WTA event.
Notes: Recent International Tennis Hall of Fame Inductee Lindsay Davenport will be honored on Stadium Court prior to Friday's first Evening Session match at the Bank of the West Classic. Davenport held the world's No. 1 ranking for 98 weeks and owns a total of 55 WTA singles titles throughout her remarkable career. She won the 1998 U.S. Open, 1999 Wimbledon and 2000 Australian Open to go along with three major doubles titles as well. The American also won an Olympic gold medal in 1996. A California native, Davenport won the Bank of the West Classic three times in singles (1998, 1999, 2004) and a tournament-record six times in doubles, including four in a row from 1996 to 1999.
At Stanford's Taube Family Tennis Center
11 a.m. -- Garbine Muguruza (Spain) vs. Daniela Hantuchova (Slovakia)
Not before 1 p.m. -- Coco Vandeweghe (USA) vs. Angelique Kerber (Germany)
Carol Zhao (Canada) vs. Ana Ivanovic (Serbia)
Not before 7 p.m. -- Victoria Azarenka (Belarus) vs. Venu Williams (USA)
Rachel Kops-Jones/Abagail Spears (USA) vs. Varvara Lepchenko (USA)/Ajla Tomljanovic (Croatia)