Samantha Stosur of Australia hits a return against Heather Watson of Britain during their women's singles quarter-final match of the WTA Hong Kong Open in Hong Kong on October 16, 2015. AFP PHOTO / Philippe Lopez        (Photo credit should read PHILIPPE LOPEZ/AFP/Getty Images)

A spirited Samanatha Stosur clawed her way into the second round of the Sydney International after a winning a marathon match against Roberta Vinci.

Stosur fought back from a set down to claim a gruelling 4-6, 7-5 7-5 victory that lasted nearly three hours in stifling Sydney heat.

“It was a very long match, a very tough match,” Stosur said.

“She knows what she's doing out there, so you've got to know how to combat that. I did that at times, not at others, but I'm glad to get through.”