NEW YORK - The father of Australia's Samantha Stosur was unable to contain his delight after his daughter upset Serena Williams.

"It all hasn't sunk in yet but it's an incredible achievement for her to go through a grand slam," Stosur's father Tony told Australia's ABC Radio from his Gold Coast home on Monday.

"She's been wanting to do this for many, many years of course, but to do it in America against an in-form Serena Williams is quite numbing really," he added after Stosur became the first Australian woman to win the US Open in 38 years.

"She was awesome, she owned it, there was no doubt about it, she was absolutely fantastic."

In a match played on the 10th anniversary of the Sept. 11 attacks on New York, Williams let her frustration get the better of her in the second set and picked up a code violation for screaming at the umpire as her title hopes slipped away.

"I was concerned the complexion of the match would change because of the distraction, and it did to some degree," Tony Stosur added.

"The crowd was absolutely behind Serena and the pressure must have been enormous on Sam to keep it together, because those sort of things can turn the match around, but she kept it together to her credit.

Stosur said his 27-year-old daughter was still coming to terms with her win when she called her family after the match.

Reuters