Michael Thompson closed out his first PGA Tour win in accomplished style at the Honda Classic at Palm Beach Gardens.

The American was nine under after carding 69 on a tough final day which saw only three other players finish under par. He ended up two shots ahead of Australia's Geoff Ogilvy and four clear of playing partner Luke Guthrie.

Graeme McDowell finished in a tie for ninth place on two under after shooting a level par final round 70 at the Florida event.

Both Thompson and Ogilvy earned their places at next week's WGC-Cadillac Championship at Doral Country Club with their results.

Thompson and Guthrie shared the overnight lead on eight under and though the former saw a long birdie putt at the second just dive left, he opened up a three-stroke lead inside the first five holes.

A monster eagle putt at the third sparked his run as, though he dropped a shot at the next, he birdied the par-three fifth to return to 10 under, while Guthrie wasted a birdie at the third with bogeys at two and five.

Two dropped shots sandwiched a birdie as Thompson reached the turn nine under and Guthrie also slipped back with a bogey at the 10th.

The latter birdied the 13th to bring the gap back to two shots but the decisive moment came at the next as the second-year professional hooked his drive out of bounds and racked up a double-bogey six.

That left Thompson four clear heading into the Florida course's feared "Bear Trap", holes 15 to 17, and he safely found the green at the first of those holes before almost holing another long putt. Guthrie's birdie attempt slipped left, though, to keep the margin at four.

Thompson was again on in regulation at the next and Guthrie responded with an aggressive shot from a fairway bunker to the back fringe, 15 feet from the hole. Guthrie got down in two but Thompson showed the first sign of nerves, over-hitting a four-foot putt which hit the right edge and stayed out.

Ogilvy, who had flown under the radar with pars until dropping a shot at the 14th, holed from almost up against the grandstand at 16 to go six under but after an aggressive tee shot at the next, he underhit the birdie putt which would have taken him within one.

Thompson made a solid par at 17, despite a whoop from a lone spectator as he putted, and Guthrie missed from inside three feet.

And needing only to find two-putt range from a greenside bunker at the last, Thompson sent his pitch rolling to within six feet and rattled in the putt for a two-stroke win.

He told Sky Sports 3: "It was just about sticking to my game plan. All through the week I'm just trying to find it in the dirt.

"This week was magical, I kept feeling it, kept believing - my wife was super-encouraging and all in all it's just a wonderful experience."

Ogilvy birdied the last to finish seven under, and one under for the day.

He said: "I played really well, it was a little frustrating with the putter but I was happy with how I hit the ball. Anything under par out here is a good score today

"It's probably not as dramatic as it looks but it's a nice bonus. I thought 'this has to go in' and then it hangs on the edge, then it drops to give me a chance."

Guthrie dug deep for a closing birdie which left him alone in third at five under, ahead of a group at three under which featured Englishmen Justin Rose and David Lynn.

Ryder Cup star Keegan Bradley joined the pair along with compatriots Erik Compton, for whom it was a first top-10 finish on the tour, and Lucas Glover.

Lee Westwood slipped back to two under after a closing 74, finishing level with McDowell, major winner Charl Schwartzel and Canada's Graham DeLaet.