PALM BEACH GARDENS, Fla. -- South Korea's Sungjae Im captured his first PGA Tour victory by shooting 4-under 66 in Sunday's final round of The Honda Classic at Palm Beach Gardens.

Im, 21, finished at 6-under 274, one stroke ahead of Canada's Mackenzie Hughes and two shots in front of England's Tommy Fleetwood, the third-round leader.

Im birdied four of his first five holes and then played the famed Bear Trap, holes Nos. 15, 16 and 17, in 2-under par. He birdied the par-3, 180-yard 15th and the par-3, 148-yard 17th with sensational tee shots over water.

"The last four holes, I just wanted to get a little bit more aggressive rather than be tentative on those holes," Im said through an interpreter. "I was hitting the ball really good and felt like I could get at those pins. After the birdie on 15 and after hitting the green at 16, I felt pretty good going to 17 and 18."

Hughes also shot a final-round 66 thanks to five birdies and one bogey, he latter coming on the par-4, 427-yard 16th.

Fleetwood, seeking his first PGA Tour victory, began Sunday with a one-shot advantage -- his first 54-hole lead on the Tour. But he shot 1-over 71 despite starting his final round with two birdies. He failed to sink another until the 17th hole and had four bogeys, including a 6 on the par-5, 551-yard 18th on which his second shot found water.

Im was in the clubhouse as Fleetwood played the final hole on tough PGA National. He became the seventh South Korean to win on tour.

"I've been in this spot many times, and just gaining the experience throughout the weeks just helped me stay in the moment," said Im, the PGA Tour's rookie of the year last season. "The other times I came close really helped, especially on the last few holes."

Daniel Berger (69 on Sunday), Brendan Steele (71) South Korea's Byeong Hun An (67) and England's Lee Westwood (70) finished tied for fourth at 3-under par.

Gary Woodland (67), Russell Henley (69) and Australia's Cameron Davis (68) tied for eighth at 2-under.

England's Luke Donald (72) was among six players finishing 1-under and tied for 11th place. A total of 16 players finished below par.