Williams, who was still on probation over an in incident at the 2009 U.S. Open, escaped a more severe penalty after officials ruled Sunday's incident was not a major offence.
"Williams' conduct, while verbally abusive, does not rise to the level of a major offense under the grand slam code of conduct," tournament referee Brian Earley said in a statement.
In 2009 she was placed under probation for her foul-mouthed tirade during her 2009 US Open semi-final loss to eventual champion Kim Clijsters.
She was fined $82,500 (£52,000) and warned that the fine would be doubled and she could be suspended from other grand slams if she committed another "major offence" in the next two years.
The probation was due to expire after the US Open.
After losing the first set 6-2 in 31 minutes, Williams lost her temper early in the second set when she was docked a point for celebrating a winner with a loud "Come on!" just as Stosur was about to try and return the ball.
Williams was issued with a code violation after arguing with the umpire then continued berating her when she sat down at the change of ends. At the completion of the match, she did not shake the official's hand.
"If you ever see me walking down the hall, look the other way because you're out of control," Williams told the umpire.
"You're out of control. You are unattractive inside.
"Code violation for this? I expressed myself, we're in America last time I checked. Don't look at me. Don't look my way."