The result made her Australia’s first female grand slam champion since Evonne Goolagong Cawley secured her second Wimbledon title in 1980.
It was the first time the nation had claimed the women’s singles crown at the tournament since Margaret Court Smith in 1973.
But the match was not without controversy, with Williams berating the chair umpire after receiving a one-point penalty for verbal hindrance.
The 13-time grand slam champion walked out onto court following emotional September 11 tributes ahead of Stosur, with the players hitting up in light rain.
Fortunately for under-fire officials, it did not last long and play started on time with a calculating Stosur taking advantage of a nervous Williams to capture the first set in 31 minutes.
But the match looked like turning at the end of the opening game of the second set following a controversial decision by the chair umpire.
Williams shouted “come on”” just as Stosur went to hit a ball on the baseline and the chair umpire penalised the American under the hindrance rule.
The decision handed Stosur an early break of serve and it infuriated Williams as she directed some sharp words at the chair umpire.
It also woke up the crowd who booed the decision and a fired-up Williams then broke Stosur’s serve for the first time in the match.
Williams called the chair umpire a “hater”.
“If you ever see me walking down the hall, walk the other way,” she said.
The incident revived memories of Williams’ ugly outburst at a lineswoman during her semi-final loss to Kim Clijsters at the 2009 US Open.
The incident seemed to rattle Stosur for a couple of games but she held tough and took a break for a 4-3 lead in the second set.
The Queenslander yelled out “Come on”‘ as she took a 5-3 lead before taking the match on her third championship point by ripping a forehand winner.