Serena and Venus Williams made a successful transition to clay, easing through their opening matches with straight set victories at the WTA Tour's Charleston tournament.
Fifth seed Serena, the 2008 Charleston champion, hammered 11 aces in overpowering last year's runner-up Elena Vesnina, 6-3, 6-4, in a second round match at the $740,000 clay court event.
World No. 87 Venus, who returned to the tour last month in Miami after being out seven months due to illness, needed just 79 minutes to dispatch qualifier Iveta Benesova of the Czech Republic, 6-4, 6-3, in a first round match.
Seven-time Grand Slam champion Venus is fresh off an impressive comeback showing in Miami where she won her first four matches of her return.
"Miami was definitely a whirlwind," Venus said Tuesday. "A lot of times I ended up the victor at the end of these matches and I didn't really know how it happened."
The Williams sisters did not play in last month's prestigious Indian Wells tournament because of a boycott that began in 2001 when fans booed them.
Venus received a wild card invitation into the draw of the Charleston event, which she won in 2004. She booked a clash with seventh-seeded Serbian Jelena Jankovic, who enjoyed a first-round bye.
Venus will be put to the test on Wednesday as Jankovic has won their last four matches on clay and holds a 6-5 lead in career contests. Jankovic routed Venus, 6-0, 6-1, in their most recent meeting two years ago in Rome on clay.
"It's a great surface for her, and she always gets comfortable on clay, so I know I have to play well," Venus said. "We've had some things we've been dealing with, with injuries, so it'll be an important match for both of us.
"I'll definitely have to be patient and try to move forward the best I can."
Venus finished out of the top 100 in the world last year for the first time in 15 years after a season plagued by injury and illness.
Venus withdrew from the second round of the US Open, where she revealed she had been diagnosed with the auto-immune disorder Sjogren syndrome, and did not play again until making it to the quarter-finals at Miami.
Serena, who was given a bye through the first round, saved six of seven break points chances and won 73 percent of her first-serve points in the 85-minute match.
Vesnina was runner-up to Denmark's Caroline Wozniacki here last year.
Serena advances to the third round where she will play either 17th seed Marina Erakovic of New Zealand or unseeded Anna Tatishvili.
In other matches Tuesday a pair of Aussies won their second-round contests in straight sets.
Second seeded Samantha Stosur beat American Jamie Hampton, 6-0, 7-5 and Anastasia Rodionova surprised 10th seeded Anabel Medina Garrigues, 7-5, 6-3.