American Ryan Palmer kept his cool to hold off playing partner Robert Allenby of Australia with a birdie at the par-five last to win the Sony Open by a shot Sunday. Tied for the lead overnight with the more experienced Allenby, Palmer fired a four-under-par 66 at Waialae Country Club to clinch his third PGA Tour title. Two ahead with eight holes remaining in a widely fluctuating final round, Palmer twice stumbled with bogeys before his chip from just off the 18th green struck the flagstick and ended up inches from the cup. He tapped in the birdie putt for a 15-under total of 265 while Allenby, seeking his first PGA Tour victory in nine years, had to settle for second place after closing with a four-birdie 67. American world No. 3 Steve Stricker, one of four players who held at least a share of the lead on Sunday, finished third at 13 under after signing off with a sparkling 65. Double US Open champion Retief Goosen of South Africa was a further stroke back in fourth after shooting the lowest round of the week, a sizzling 62 featuring nine birdies and a lone bogey. Palmer briefly moved two strokes clear after knocking in a five-foot birdie putt at the 10th before slipping back with a bogey at the par-three 11th where he found a bunker off the tee. Stricker then joined him at 13 under after conjuring a surprise birdie at the par-four 13th, hitting his second shot from a fairway bunker to 16 feet and coolly sinking the putt. Allenby made it a three-way logjam at the top when he rammed in a 22-footer to birdie 12 but seconds later Palmer regained control when he sank a 13-footer on the same green. Stricker faltered with a bogey on 15 where he pulled his approach into a greenside bunker and Palmer also stumbled after finding bunkers off the tee and with his second shot on 13. However, Palmer again forged one ahead of the chasing pack when he knocked in a 10-foot birdie putt at the 14th where Allenby missed his own attempt from eight feet. Allenby turned on the pressure with a superb approach to three feet at the par-four 15th but Palmer responded when his second shot ended up seven feet from the cup. Palmer was visibly annoyed after pushing his birdie putt past the right edge before the Australian knocked in his to join the American in a tie for the lead at 14 under. Stricker closed to within a stroke by draining a 24-footer at the par-three 17th but he failed to birdie the last and had to settle for third place. Palmer and Allenby were deadlocked at 14 under playing the last before the American sealed victory with a fortunate birdie.