American Nick Watney carded a two-under 71 to record a comfortable three-shot win at The Barclays on Sunday (local time), with Greg Chalmers the best of the Australians but well off the pace.
Watney, who has had only three top-10 finishes this season after a strong 2011, finished at 10 under at the Black Course at Bethpage State Park.
Chalmers (four under) was in outright ninth, six shots behind Watney.
Geoff Ogilvy and John Senden (both two under) were tied for 19th, while Jason Day produced a brilliant five-under 66 to end up at one under and tied for 24th.
Rod Pampling (two over) and Adam Scott (four over) were further back.
World number 35 Watney took the lead in the FedEx Cup playoffs, collecting US$1.44 million for the fifth victory of his career.
Spanish overnight leader Sergio Garcia, who won the Wyndham Championship last week, holed five bogeys in his four-over 75 to end up tied for third.
American Brandt Snedeker finished second on seven under, a shot clear of Garcia and Dustin Johnson.
In the day's final pairing, Watney continued to put Garcia - aiming to become the first player since Tiger Woods in 2009 to win in consecutive weeks on the PGA Tour - under pressure.
Watney, starting the round two shots behind, holed three birdies and a bogey on the front nine, while Garcia managed two bogeys to go with his birdie at the par-four sixth.
The 31-year-old Watney moved further ahead with a birdie at the 10th, where Garcia produced a bogey, before easing to a comfortable win.
"I didn't strike the ball very well at the beginning of the season," Watney said.
"Probably the first three or four months of the year, really, I didn't hit it very well, and I didn't putt as consistently as I did last year.
"Mentally, I definitely started pressing a little bit. Thursday, Friday, Saturday rounds became really, really important to me. You definitely want to play well, but there's so much more golf to be played, and I kind of lost sight of that."
Canadian Graham DeLaet stormed home with a six-under 65 to be tied for fifth at five under alongside South African Louis Oosthuizen, Englishman Lee Westwood and American Brian Harman.
Meanwhile, Tiger Woods finished the tournament with his worst score of the season - a 76 - to end up tied for 38th at one over.