Having won just seven matches since the start of March and just one set in her four encounters with Stosur, the pre-match form book did not augur well for Razzano.
However, the Frenchwoman is a mercurial talent - illustrated by her epic win over Serena Williams earlier this year at Roland Garros - and in the first set she threw the form book out of the window, dictating the rallies and preventing Stosur from establishing any sort of rhythm on her trademark forehand wing.
After being a distant second best for the entire opening set, Stosur capitalized on a slight dip from her opponent to break serve at the start of the second and secure a belated foothold in the contest. A further break in the fifth game proved enough for her to take the set and with the momentum now in her favor she repeated the trick in the decider to secure a 16 62 64 win.
"She's one of those players who is very tough to play when she's on her game," Stosur said. "She stays on the baseline, she hits the ball hard and it's hard to get on top of the point.
"When she's just that little bit off, then it's important for me to hit my heavy ball and take control, which is what I tried to do in the second and third sets."
Stosur has met Hampton once previously - winning 60 75 earlier this year in Charleston - and is wary of the threat posed by the ever-improving young American.
"We played earlier this year in Charleston, I think I won in straight sets but she's a talented player who's quite young and has had some good wins," Stosur added. "For her to win two matches here she must be playing well and it's one of those matches where I need to be ready.
"I'll try and take care of my game, do what I like to do and be aggressive out there."