Na's final-round cushion evaporated thanks to a triple-bogey at the 10th hole and a bogey at the par-five 16th after he hit his second shot into a pond.
Both players made back-to-back birdies at the 12th and 13th holes and another at the 15th to keep the lead the same, but a two shot swing on the 16th after Na found the water gave Cantlay the advantage for the first time. He left what appeared to be a chunky second shot more than 40 feet from the pin and his putt for birdie came up 6 feet short. Only Brooks Koepka (four) has more wins in that span. "Tends to do that sometimes, and when it does, if I'm hitting it halfway decent I feel like I can win".
The Shriners Hospitals for Children Open was the fourth regular-season event on the PGA Tour's 2019-20 schedule and the first to go to a playoff this season. Na, who lives in Las Vegas, also won this event in 2011 and entered Sunday with a four shot lead. He remained one shot in front of Cantlay only because Cantlay also bogeyed 10.
Both players birdied the first extra play-off hole, before a par at the next hole was enough for Na to secure his fourth PGA Tour title and see him join Jim Furyk as the only multiple victor of the event.
Knight had missed the cut in half of her 18 starts on the LPGA Tour and assumed she would be going back to the qualifying series.
"It came down way to close", Na said.
They finished at 23-under 261.
Adam Hadwin (66), also of Abbotsford, was 9 under, Roger Sloan (66) of Merritt, B.C., was 3 under, Mackenzie Hughes (71) of Dundas, Ont., was 1 under and Graham DeLaet (72) of Weyburn, Sask., playing in his first tournament in nearly two years due to a back injury, was 5 over.
Joel Dahmen ended up at 8 under, too, settling for a 64 after playing the first 10 holes in 9 under.
Na sank a four-foot par putt at the second extra hole at TPC Summerlin to see off Cantlay, but he should have had the title sewn up well before.
"Look, you need some luck to have some putts lip-in here and there and I've been getting a little of that".
Pat Perez (68) finished outright third at 21 under, a shot ahead of defending champion Bryson DeChambeau (63), Adam Hadwin (63) and Brian Stuard (67). He followed that up with a 29-foot putt for a birdie on the 14th hole (par 3) to bring him to 3-under-par for the round.