The in-form John Senden was the highest-ranked Australian as Hunter Mahan secured his second PGA Tour title of the season with a one-shot win at the Houston Open on Sunday (local time).
Queenslander Senden, who has three top-10 finishes on the PGA Tour this season, shot a two-over 74 in the final round to end up tied for 18th, eight shots behind Mahan.
It was a solid result for Senden as he prepares for the upcoming Masters at Augusta this week.
The next best Australians were Marc Leishman (seven-under), Rod Pampling (six-under) and Mathew Goggin.
Robert Allenby and Aaron Baddeley were among those who missed the cut after the second round.
Mahan, winner of the WGC-Accenture Match Play Championship in February, carded a one-under 71 to finish the tournament at Redstone Golf Club at 16-under.
Carl Pettersson was second a shot back, while overnight leader Louis Oosthuizen could only manage a three-over 75 in the final round to finish outright third.
World no.14 Mahan's short game was excellent, and birdies on the ninth and 10th holes helped him to his fifth PGA Tour title.
A bogey on the par-three 14th allowed Pettersson to get within a shot, but the Swede narrowly missed birdie putts on the 16th and 18th as his challenge faded.
Mahan, who completed the ideal preparation for the Masters, moved top of the FedEx Cup rankings and is projected to leap to number four in the world.
South African Oosthuizen, the 2010 British Open champion, double-bogeyed the fifth hole and did likewise on the eighth.
Bogeys on the ninth and 10th followed as he fell out of contention despite finishing with three birdies on his last seven holes.
Three-time Major winner Ernie Els, who needed to win the tournament to qualify for the Masters, will be absent from Augusta for the first time since 1993 after ending up tied for 12th.
Americans Jeff Overton, Keegan Bradley and Phil Mickelson shared fourth with England's Brian Davis.Lee Westwood, also of England, struggled with the putter to end up tied for 21st at seven-under.