The former world No 1 fired seven aces and hit a first-serve percentage of 71, in addition to a barrage of sizzling shots that ended the match in 57 minutes at the Ariake Colosseum. However, Sharapova admits she may no longer be feared.
"In some way I wish I could say I was vacationing for 10 months and then all of a sudden I kind of wanted to play again," Sharapova said.
"But every single day I was trying to find a way to get back out there. It's hard when something is taken away from you. For me it was about three or four months where I really didn't pick up a racket.
"That was the first time in my life I've had to do that since I started playing tennis. It was really strange waking up and knowing you're not going to go out on the court."
Sharapova has climbed to 25th in the world since returning to action in May after shoulder surgery.
The three-times grand slam singles champion said she had reached a different stage in her career.
"It's obviously like a second career in a way when you're almost out of the rankings and you're working your way up and you're not feared anymore," she said.
Sharapova's victory over Stosur propelled the former Tokyo champion into the last 16.
Yet to add to her 19 career singles titles since her return, Sharapova insisted she would be a major force again.
"Grand slams are still the focus," the 22 year-old said. "I know if I do well and perform at a certain level which I know I can then those goals will be met."
