The world number one tennis player, Switzerland's Martina Hingis, has progressed to the third round of the Acura Classic tournament in California.
Hingis, who had complained at Wimbledon of being mentally worn out by touring, bested American Lilia Osterloh 6-1 6-4.
"I played better than I expected," said Hingis, who suffered tendinitis in her lower back prior to Wimbledon and was unable to practice leading up to the Grand Slam event.
"I played a near perfect set and a half and then got a little tired," she said.
Six years on circuit
At 20, Hingis has spent six-and-a-half years on the circuit. To maintain the world number one ranking she has held for 199 weeks, she has rarely taken off more than a month at a time.
Although this has allowed her to amass more points and titles than her main rivals, she has come up short at the Grand Slams in her last 10 attempts.
"As a number one, you would always expect to do more, but the other players would be happy [being number one]," said.
Hingis is more than 1,100 points ahead of number two Jennifer Capriati. However, she could lose the top spot at the forthcoming U.S. Open.
Australian Nicole Pratt, in her second round match, beat Russian Anna Kournikova 6-7 6-1 6-3 in singles play. Kournikova was back in action for the first time in six months following surgery on a foot stress fracture.
Kournikova said a pin had been placed in her foot in April to speed the healing process following injury in February. "Every time, every month you are waiting and waiting," the 20-year-old Russian said after Tuesday's defeat. "It got a little frustrating."
Kournikova had won her first round doubles match partnering Hingis on her competitive return on Monday.
swissinfo with agencies