Briny Baird managed a 1-over 72 to finish alone in third place at 8-under-par 276. The finish was good enough to earn Baird a spot in the top 30 on the money list and an invitation to next week's season-ending Tour Championship.
Goosen was a late entry into the field this week after passing on the Volvo Masters Andalucia on the European Tour. The decision to play in the U.S. proved to be a good one as Goosen made it three straight years with a victory on the PGA Tour, dating back to his 2001 U.S. Open title.
'It's starting out to be a great year now for me,' said Goosen, who pocketed $864,000 for the win. 'It was a bit of a slow start and so on. It's turning out to be a very good year.'
The South African carried a two-shot lead over Baird into the final round on the Copperhead Course at Westin Innisbrook and jumped out of the gate with a birdie at the first before finding trouble with a bogey at the very next hole.
Goosen dropped another shot at the par-4 sixth but hit his second shot inside four feet for a birdie at the seventh.
The 34-year-old faltered again with a bogey at the ninth but managed to recover with a 12-foot birdie putt at the 10th.
Goosen then birdied the 13th to regain a two-shot edge and got up and down for a birdie at the par-5 14th to begin to pull away from his challengers.
He coasted down the stretch and held on for the victory despite a bogey at the par-3 17th.
'I knew I just had to hang on the last few holes,' said Goosen. 'I felt fairly comfortable.'
Singh, who has now finished no worse than second in each of his last four starts, padded his lead over Tiger Woods in the race for the money title.
'I have to play a solid tournament next week,' said Singh, who has two victories in that span. 'I don't think I have to win to win the money title, but I would like to win again next week.'
A victory would have practically secured the top spot on the money list no matter the outcome of the Tour Championship, but Singh was unable to overcome Goosen's solid play.
Singh picked up his first birdie of the day at the second but stumbled with a bogey at the sixth. He ran home a six-foot putt for a birdie at the seventh to briefly pull within one of the lead but gave that shot back with a bogey at the ninth.
The 40-year-old tallied two birdies and a bogey on the inward half to take second place alone at 9-under-par 275.
'Retief played solid all day and he deserved to win,' said Singh, who shot a 70 on Sunday. 'I am a little disappointed I didn't win. I thought I had a good chance.'
Baird struggled early with a double bogey and a bogey on the front side but put together a strong finish to earn a coveted spot in the top 30.
The 32-year-old had three birdies and a bogey over his last five holes to climb to No. 22 on the money list.
Chad Campbell and Tim Petrovic shared fourth place at 6-under-par 278.
Thomas Levet had a bogey at the 17th that cost the Frenchman a spot in the top-125 on the money list. Levet was joined by Davis Love III and Dan Forsman at 5-under-par 279.
'This year I had a long season,' said Levet. 'I enjoyed my time in America. It was very, very good.'
Stephen Ames, Peter Lonard, Brad Faxon and Geoff Ogilvy tied for ninth at 4-under-par 280.
K.J. Choi, who won this event last year, finished in a tie for 40th at 2-over-par 286 but it was enough to earn the South Korean the 30th spot on the money list and an invitation to the Tour Championship.
On the other end of the spectrum, Esteban Toledo, who missed the cut this week, finished with the 125th spot on the money list and will retain his card for next season.