LOS ANGELES (AFP) - Seven-time Grand Slam Champion Venus Williams powered into the third round of the WTA claycourt tournament at Charleston on Wednesday with a 6-4, 6-2 victory over Alison Riske.
Williams, seeded third and seeking a 50th career WTA title this week, fired 20 winners.
She displayed a sharp service game, and broke Riske five times in a match lasting less than an hour and a half.
"It wasn't easy," said Williams, who won the title on the green clay of Charleston in 2004.
The US veteran's aggression at the net paid off, and she thought her height advantage might have helped her out as well.
"Maybe that's an unfair advantage," said Williams, who was coming off opening match exits at Indian Wells and Miami.
"I think experience definitely helped. She has played good matches and won titles, so just the experience of playing those important points helped me a little more today."
Williams next faces Kazakhstan's Yulia Putintseva for a place in the quarter-finals.
Putintseva defeated 15th-seeded German Sabine Lisicki 7-5, 4-6, 6-3.
In other matches on Wednesday, seventh-seeded American Sloane Stephens defeated Danka Kovinic 6-4, 6-3, but former Charleston finalists Lucie Safarova and Madison Keys both bowed out.
America Louisa Chirico sent fourth-seeded Safarova packing 6-3, 6-3, while Germany's Laura Siegemund rallied for a 6-7 (3/7), 6-4,6-4 win over eighth-seeded Keys.
"I think it was a very high level that we both played," said Siegemund, who used an array of drop shots to good effect.
"I think it was a great match in general. I had chances in the first set, had a set point, but she played very well in the tough moments so I had to be patient and wait for more chances to come." There was a disappointing injury exit for Canadian Eugenie Bouchard, who had just evened her match against Lourdes Dominguez when she was forced to retire with an abdominal injury.
Spain's Dominguez was leading 6-4, 1-6, 1-0 when Bouchard decided she couldn't continue.
"It's the same one (from last year), which is why I'm concerned and why I did retire," said Bouchard, who played at last year's Wimbledon with an abdominal muscle tear and said she didn't want to repeat the mistake of making the injury worse.