The Belgian was ruthless in her 53-minute demolition of the 39th-ranked Australian, joining holder Mary Pierce in getting off to a winning start after a bye at this costal golf resort.

Clijsters won both of her Fed Cup matches against the US last month and lifted the first title of the summer hardocurt season last weekend in northern California at Stanford.

Sixth seed Pierce had to struggle for more than two and a half hours before squeezing out a 6-1, 6-7, 7-6 victory over Sybille Bammer.

The 2000 Roland Garros champion was playing for the first time since suffering a right foot partial tendon tear in February. Her last match was the Paris indoor final, which she lost to Amelie Mauresmo.

Clijsters couldn't have been more pleased with her one-way rout.

"It's nice to keep playing my best tennis. I knew I had to be on my toes today, she can play well and I know her game can be tough.

"I'm very pleased to have gotten out in two sets."

Nadia Petrova's return after two months away with a hip problem fell well short as the Russian third seed lost badly to compatriot Anna Chakvetadze 6-3, 6-7, 6-2.

"I couldn't do anything, it was all errors for me," lamented Petrova, who last played in a first-round defeat at the French Open in late May.

Clijsters has been on a tear since Wimbledon, her only loss coming to rival Justine Henin-Hardenne in the grass-court semifinals.

She next plays Jelena Jankovic, who beat Alana Bondarenko of Ukraine 6-1, 7-6. Another Serb, 14th seeded Ana Ivanovic dispatched 33-year-old American Amy Frazier 6-3, 6-2.

Pierce liked the look of her game after her long injury absence.

"It was a good start, I didn't know what to expect. "There's not much missing from my game."

The 31-year-old added: "I can't remember when I was so happy and excited to be back on court competing again. I competed really well, my game felt okay."

The Frenchwoman had to struggle after missing a chance to close out a straight-sets win as she went wrong on three match points.

Forced into a concluding third set she then had to recover from a break before levelling at 5-all against Bammer, ranked ranked 46th.

Pierce recovered her poise in the tiebreaker, earning the hard-fought win on her fourth opportunity of a long afternoon.

"Missing those match points was a matter of two or three weeks of training," said Pierce. "This match was what I had expected.

"In the second set, my energy level dropped. But I was doing the best with what I had. I need matches and training, the US Open is my goal."

Russian fourth seed Elena Dementieva got on and off court with efficiency in a 6-2, 6-2 thrashing of American Ashley Harkleroad while Slovak 11th seed Daniela Hantuchova beat Olga Savchuk of Ukraine 6-2, 6-4.

Vera Zvonareva advanced when China's Peng Shuai was unable to continue because of heat exhaustion, handing the Russian a 3-6, 7-6, ret, win.

"I could see she was having problems with the heat," said Zvonareva, winner of two titles since June including Cincinnati last month. "I felt fine and wasn't thinking about the weather.

Finn Emma Laine lined up a Thursday clash with Pierce after winning the longest match of her career, a three-hour, 20-minute marathon over Elena Vesnina 6-7, 7-6, 6-4 in which both women required treatment on court.