(CNN) -- Australia's Samantha Stosur produced one of the biggest shocks in U.S. Open final history, beating Serena Williams in straight sets at Flushing Meadows to secure her first Grand Slam success.
Williams, bidding for her fourth U.S. Open crown, had gone into the match as a hot favorite despite a troubled year blighted by injury and serious illness.
But Stosur never allowed the American, who was cheered on by a patriotic New York crowd on the 10th anniversary of 9/11, to settle -- claiming a spectacular 6-2 6-3 triumph in 73 minutes, as Williams lost her cool following a contentious umpiring decision.
"I had one of my best days and I'm very fortunate that I had it on this stage in New York," Stosur said after the match.
"Ever since I started playing, it was a dream of mine to be here one day, and now my dream has come true."
Stosur, whose run to the final included a marathon third-round victory over Nadia Petrova that lasted a tournament record three hours and 16 minutes, continued: "Serena, you are a fantastic player, great champion and have done wonders for our sport.
"Thanks to everyone back home for supporting me. All my friends, family and everyone else, thanks so much for supporting me. I look forward to coming back home."
Although she was only seeded 28th, Williams came into the tournament bang in form after winning two warm-up events -- including victory over Stosur in the final of the Rogers Cup in Toronto.
And the American was mightily impressive in dismantling world number one Caroline Wozniacki in the semifinals, while ninth seed Stosur struggled to beat unseeded German Angelique Kerber in three sets in the other semi.
With emotions high among New Yorkers, on a poignant day for the city, a Williams win looked set to provide the United States with a fitting end to a difficult occasion.
But Stosur, whose only previous Grand Slam final appearance came last year when she lost the French Open to Francesca Schiavone, did not read the script, dominating the opening set against the 13-time Grand Slam champion, who had reached this stage without dropping a set in the tournament.
Stosur broke Williams to lead 2-1 and then won the last 12 point of the set in an impressive display of pace and power.
Then came the talking point of the match. Williams had already saved one break point in the first game of the second set.
However, on the second break point, the American shouted "come on" as she unleashed a fierce forehand before Stosur had reached the ball.
Umpire Eva Asdaraki immediately penalized Williams for "intentional hindrance," and the point and the game went to Stosur.
Williams reacted angrily to the decision and was then given a code violation for verbal abuse.
The American immediately broke back and then held serve but continued to berate the umpire at the changeover, as her composure ebbed away.
"Don't even look at me -- If I see you in the corridor don't even walk past me," shouted the 29-year-old. "A code violation for expressing my opinion?, we're in America -- you're unattractive inside"
Stosur then broke serve to take a 4-3 lead and broke Williams again to clinch a famous victory -- becoming the first Australian women's winner at Flushing Meadows since Margaret Court in 1973.
When asked about the incident after the match, Williams said: "I was just doing my best. I hit a winner but I guess it didn't count. It wouldn't have mattered anyway because Sam played really well and she is a great player."
She continued: "Six months ago I didn't think I would be standing here. I didn't think I would even be standing, let alone be here."
Stosur's victory means she joins Li Na and Petra Kvitova as first time Grand Slam winners this year.