Miami - World number one Jason Day overcame a sluggish start on Sunday to win the US PGA Players Championship, firing a final-round one-under-par 71 to complete a wire-to-wire victory.
Day matched the TPC Sawgrass course record with an opening-round 63 and followed with a 66 on his way to a 72-hole total of 15-under 273 for a four-stroke victory over American Kevin Chappell.
"This is up there," Day said when asked the magnitude of his 10th career US PGA triumph in a tournament often seen as golf's unofficial fifth major.
"I just wanted to win this so bad. This could possibly push me over to get into the Hall of Fame one day and I'm just glad I managed to win it."
The 28-year-old Australian took a top prize of $1.89 million at the $10.5 million event, collecting his seventh win in 17 starts - his fifth in a row when leading after 54 holes.
"I'm going to hold this memory for a long time," Day said.
The Aussie made bogeys at the sixth and ninth holes to carry only a two-shot edge onto the back nine, but responded with key birdies at 10 and 12 and another at the par-5 16th to hold off a host of rivals.
"I was really nervous on the front side and it showed," Day said. "Then on the back side I was able to hold on."
Chappell fired a 69 to finish second on 277, one stroke ahead of fellow Americans Justin Thomas, Ken Duke, Matt Kuchar and Colt Knost with Italy's Francesco Molinari and Japan's Hideki Matsuyama sharing seventh on 279.
It was the second start-to-finish triumph of the season for Day, who also led after every round in taking the Arnold Palmer Invitational at Bay Hill. Since 1980, only Tiger Woods has had two wire-to-wire US PGA wins in the same year.
Day's impressive victory run over the past 10 months includes his first major title at last August's PGA Championship, the Barclays and BMW Championship in last year's US PGA playoffs and this year's World Golf Championships Match Play.
Day, who stretched his margin over second-ranked Jordan Spieth after the American missed the cut, has top-10 finishes in the past four majors and will try to add to his major win total by dethroning Spieth in next month's US Open at Oakmont.
"I'm very motivated to stay at number one," Day said. "This definitely gives me that extension on the gap between one and two and I'm very much looking forward to the rest of the year."
The victory made Day the third reigning world number one to capture the Players, joining Woods and Greg Norman, and the fourth Aussie to win the event after Norman, Adam Scott and Steve Elkington.
Day's caddie for a decade, Colin Swatton, said his man battled his instincts down the stretch to claim the victory.
"All day it was just stay patient, pick your moments and let the course come to us. He's like a Formula One (guy). He wants to have the hammer down all the time. It's hard at times for him not to hit the driver. It showed a lot of confidence, patience and trust."
Day's four-shot lead when the round began was halved as he made the turn, at which point he was the only player not to have a broken par on any hole in the last round.
The Aussie stumbled to 12-under while Thomas birdied three of the final five holes to shoot 65 and reach the clubhouse on 10-under with five rivals on 9-under as Day's back nine loomed.
Day answered the challenge by sinking 17-foot birdie putts at the 10th and 12th holes to reach 14-under - four shots ahead of Duke, Knost, Kuchar, Molinari and Thomas.
Day sank a four-foot birdie putt at 16, parred the tricky par-3 17th with its island green and parred the 72nd hole to claim victory.
Third-ranked Rory McIlroy shot 70 to share 12th on 281.
Leading scores after Sunday's final round of the US PGA Players Championship (par 72, USA unless noted):
273 - Jason Day (AUS) 63-66-73-71
277 - Kevin Chappell 71-67-70-69
278 - Justin Thomas 70-68-75-65, Matt Kuchar 71-67-72-68, Colt Knost 72-63-74-69, Ken Duke 74-67-65-72
279 - Francesco Molinari (ITA) 66-69-72-72, Hideki Matsuyama (JPN) 68-71-67-73
280 - Graeme McDowell (NIR) 72-70-69-69, Daniel Berger 66-72-73-69, Alex Cejka (GER) 67-67-72-74
281 - Adam Scott (AUS) 73-65-75-68, Rory McIlroy (NIR) 72-64-75-70, Bryce Molder 70-68-72-71, Retief Goosen (RSA) 70-68-70-73
282 - Boo Weekley 66-69-78-69, Shane Lowry (IRL) 65-68-78-71, Cameron Tringale 65-69-75-73
283 - Justin Rose (ENG) 65-74-78-66, Russell Knox (SCO) 68-67-80-68, Jerry Kelly 67-68-77-71, Jonas Blixt (SWE) 67-67-75-74
284 - Paul Casey (ENG) 68-72-76-68, Scott Piercy 70-68-75-71, Ryan Palmer 67-70-75-72, Daniel Summerhays 69-69-71-73, Kim Si-Woo (KOR) 68-70-72-74