Defending champion and second seed Kim Clijsters survived a second-set wobble to reach the second round of the US Open on Monday by defeating Greta Arn of Hungary 6-0, 7-5.
There were wins also for third seed Venus Williams, fifth seed Samantha Stosur of Australia and the woman who beat her in the French Open final, sixth seed Francesca Schiavone of Italy.
But former world number one Dinara Safina suffered more heartache as she attempts to return to her best form after a crippling back injury.
A year on from her stunning win at Flushing Meadows when she stepped out of retirement and motherhood to lift her second US Open crown, Clijsters was again in a dominant mood on the Arthur Ashe Stadium Court.
She sped through a one-sided first set in just 18 minutes, but allowed the 30-year-old Arn, ranked 104th in the world, to play her way back into the match with two breaks of serve for a 4-0 lead in the second set.
Whether it was over-confidence after the first set romp, lethargy brought on by the sultry conditions, or the lingering effects of the right thigh injury that hampered her in Montreal, Clijsters looked suddenly very uncomfortable.
She battled back to 4-3 down, but Arn served for the set two games later only to be broken by a resurgent Clijsters.
The Belgian held for a 6-5 lead and then broke Arn again to move through in 62 minutes.
The 27-year-old Belgian second seed will next play 19-year-old Australian qualifier Sally Peers, who impressed in a 6-1, 6-0 win over Aleksandra Wozniak of Canada.
"I felt I was hitting the ball well, but I lost my position and footing a bit on court at the start of the second set and wasn't aggressive enough and she started going forward a little more with some risks and put the pressure on me," Clijsters said.
"I just tried to change a few little things just with myself -- take smaller steps and make sure those feet keep moving."
There was a reasonably comfortable winning start for top American hope Venus Williams.
But there were signs in her 6-4, 6-1 defeat of Italy's Roberta Vinci that the 30-year-old third seed, who carries US hopes with sister Serena out injured, is still feeling some pain from the left knee injury that has sidelined her since Wimbledon.
"I was doing pretty good until I landed on my leg on a swing volley," she said.
"She didn't make a lot of errors so I was very happy to get through after not playing forever.
"I have a lot of shoes to fill with just one Williams here."
Surprise French Open champion Schiavone coasted past Japan's Ayumi Morita 6-1, 6-0 in just 58 minutes.
The 30-year-old Italian played the tennis of her lifetime to win in Paris in June, but since then she has struggled to reproduce that kind of form and intensity.
That was only normal, she insisted.
"When you try to reach in the top of the mountain, then you can't go more up. So you have to go down and come back up again," Schiavone said.
"I think I am doing this one. And when it's time to come back up again, I will do it. I'm working to do it."
Stosur, who has been struggling with a right arm injury, dropped the first set against Russia's Elena Vesnina before finding her best form at last in a second-set tie-break and then powering away in the decider.
"To get through the first round of a tournament that you've never really done great in is pretty pleasing. I got better and better as the match moved on," she said.
"I felt good going into the tie-break as I felt I was playing better then I sort of rolled through the third."
Among others to go through early on were Russia's Elena Dementieva, the runner-up here in 2004, when she also reached the final of the French Open. The 12th seed had too much firepower for Olga Govortsova of Belarus, winning 6-1, 6-2.
Elena Baltacha meanwhile gave a much needed boost to British tennis by defeating Petra Martic of Croatia, who beat her at Wimbledon, 6-2, 6-2, while American Melanie Oudin, a huge crowd favourite here last year when she reached the quarterfinals, ousted Olga Savchuk of Ukraine 6-3, 6-0.
There was disappointment, though, for the struggling Safina, the top seed a year ago who is now on the comeback trail after being out for three months following the recurrence of a bad back injury.
The tall Russian put on a battling display against Slovak veteran Daniela Hantuchova, but bowed out 6-3, 6-4.