World No 1 Caroline Wozniacki completed a 6-3, 6-1, win over Nuria Llagostera Vives of Spain to advance to the second round of the US Open.
The Dane smashed 22 winners in a lopsided victory that took just 80 minutes.
A finalist in New York two years ago, Wozniacki is still chasing her first Grand Slam title, giving her doubters all the ammunition they need, the Age reports.
“They can say what they want. I’ve won a lot of tournaments. I’m number one in the world. There are a lot of things to my game I can still improve, but everyone can. I’m on the right track,” Wozniacki said after the match.
Meanwhile, Serena Williams demolished Serbia’s Bojana Jovanovski 6-1, 6-1, in less than an hour.
It was a clinical and ruthless display from Williams, who has won the US Open three times.
Also winning in straight sets was World No 5 Victoria Azarenka and World No 19 Ana Ivanovic.