ORLANDO, Fla. — The way the final-round leaderboard began and the way it unfolded on a steamy Sunday at Bay Hill, Kurt Kitayama was the last player most people expected to be fitted for the traditional red cardigan sweater “The King’’ made famous as the winner of the Arnold Palmer Invitational.

In hot pursuit, right behind Kitayama’s tenuous 54-hole one-shot lead entering the day, were some of the biggest stars in the sport.

Defending champion Scottie Scheffler, the No. 2 ranked player in the world, was right there. So, too, was Rory McIlroy, ranked No. 3 and the 2018 winner of this tournament.

Then there was Jordan Spieth, Patrick Cantlay, young up-and-comer Viktor Hovland and Tyrrell Hatton, the 2020 API champion.

When Kitayama made triple bogey on the ninth hole to flip his two-shot lead into a one-shot deficit thanks to his tee shot rolling a mere 6 inches to the left of the cart path and out of bounds, the expectation of everyone (except Kitayama) was that he’d tumble down the leaderboard and cede to one of the stars.

Kitayama, after all, was chasing his first-ever PGA Tour victory in his 50th start. And something as jarring as the mess he made on No. 9 is usually a death knell to a player not experienced in those high-stress situations.

But a funny thing happened on the way to the end of the tournament as six different players held at least a share of the lead in the frenetic final round: Damned if Kitayama didn’t gather himself after No. 9, settle down and win the tournament.

“I’ve always dreamed of winning on the Tour and to finally do it, it’s pretty amazing, pretty unbelievable, really,’’ he said in the immediate aftermath of the win, looking and sounding a lot more overwhelmed than he appeared while playing the most important round of his life.

In the end, Kitayama, who’d played in 103 tournaments on 11 other tours around the world and won three times, staved off McIlroy and Harris English by a shot as he finished 9-under to their 8-under. Scheffler, Spieth, Cantlay and Hatton finished two back at 7-under.

The list of tours on which Kitayama has played includes the European Tour, Canadian Tour, Australasian Tour, Australian Tour, the Asian Developmental Tour, the Sunshine Tour in South Africa, the Japan Tour, Korean Tour, Korn Ferry Tour and now the PGA Tour.

Those experiences hardened the 30-year-old Kitayama, who’s a native of Aaron Rodgers’ hometown of Chico, Calif., to handle the heat he faced Sunday.

“You just travel to every different country, you’re dealing with logistics, food, the culture, language,’’ he said. “So, outside of golf it’s difficult. That just helps you grow as a person and when you get into situations like this … there’s tougher things.’’

After the incident on the ninth, Kitayama made seven consecutive pars until he reached the treacherous par-3 17th, which presents a long tee shot over water to a green well-protect by bunkers.

He stuffed a 6-iron to 14 feet and made the birdie putt to regain the lead at 9-under.

And he wouldn’t lose it.

The walk from the ninth green to the 10th tee is somewhat of a long trek across the back of the practice range and on that walk Kitayama told his caddie, Tim Tucker, “I don’t feel rattled at all.’’

Tucker, who used to caddie for Bryson DeChambeau, told him, “Yeah, we’ll get it back.’’

They did.

After the birdie on 17 gave him the one-shot lead with one hole to play, Kitayama hit his tee shot into the thick, juicy left rough, leaving himself 158 yards to the flag.

He hit 8-iron to the center of the green, 47 feet away from victory.

Kitayama’s lag putt for birdie came to rest on the edge of the hole, part of the ball peering down into the cup.

He marked it with a quarter and that’s when the gravity of the moment hit him. His world ranking was jumping to 19th and he was now into the Masters, British Open, PGA Championship.

His life as he knew it was changing before his eyes.

“When I marked it and walked over to Tim and [it was] just like a big sigh of relief, really … that this was really happening,’’ Kitayama said.

When it was over, those top players in the world he staved off were quick to compliment Kitayama, because they’re all aware of the arduous journey he’d taken to Sunday.

“I’m really happy for Kurt,’’ McIlroy said. “He’s been playing well for a while now, and I’m happy to see him get his first win. Kurt did real well to hang in on that back nine. He’s sort of persevered and played wherever he could get starts, and all of a sudden he’s won one of the biggest events on the PGA Tour. So, good for him.’’