SHANGHAI – Russell Knox made an unexpected trip to Shanghai and left with a most surprising victory Sunday in the HSBC Champions.

Knox became the first player to win a World Golf Championship in his debut when the 30-year-old from Scotland was flawless on the back nine of Sheshan International and closed with a 4-under 68 for a two-shot victory over Kevin Kisner.

Knox only found out a week ago Friday that he was in the HSBC Champions as an alternate when J.B. Holmes withdrew. He was in Malaysia and had to scramble to get a Chinese visa, arriving in time for one practice round with his wife, Andrea, as his caddie.

Then, he held off a world-class field for his first PGA Tour victory.

”I always thought I was going to win a big one for my first one,” Knox said. ”This is going to take a long time to sink in.”

Li Haotong, the 20-year-old from China who felt like a rock star all week, faded quickly with a bogey-double bogey start. But he kept it entertaining the whole way around and at least achieved his goal of finishing in the top 10. Li saved par on the 18th hole for a 72 to tie for seventh, the highest finish ever by a Chinese player in a PGA Tour event.

Jordan Spieth, starting the final round three shots behind, never got anything going. Two birdies on the back nine at least allowed him to post a 70 and tie for seventh, enough for the 22-year-old Texan to return to No. 1 in the world.

Kisner made birdie on the 18th for a 70 to finish alone in second, his fourth runner-up this year. The other three were playoff losses.

Danny Willett of England closed with a 62 and was briefly tied for the lead. He tied for third with Ross Fisher (68), but at least made up significant ground on Rory McIlroy in the Race to Dubai on the European Tour. McIlroy, who closed with a 66 and tied for 11th, is not playing the BMW Masters next week in Shanghai. That means the Race to Dubai will be settled in the final event at the DP World Championship in Dubai.

Dustin Johnson had a 71 and finished four shots behind, though he will look back at one great shot that cost him. One shot behind Knox on the par-5 eighth, Johnson hit a wedge that looked as though it would land a few feet behind the cup for a tap-in birdie. Instead, it hit the pin and caromed hard off the green and down into a creek, turning a sure birdie into a double bogey. He never quite recovered.

Knox, though, would have been tough to beat. He finished at 20-under 268.

His day started early, and it paid off. Knox chose not to finish the third round Saturday evening because of darkness, instead returning in the morning chill to play the par-5 18th. He hit wedge to 3 feet for birdie to tie Kisner for the 54-hole lead.

Kisner made bogey on the opening hole, Knox ran off two quick birdies and he was on his way.

The only sign of a struggle came when he missed a 3-foot birdie putt on No. 8 and then failed to get up-and-down for par on the ninth. He was tied for the lead at 17 under with Willett, Fisher, Kisner and Branden Grace, but not for long. He made a 10-foot birdie at No. 10 and another birdie on the 11th.

The clincher came at the reachable par-4 16th. Knox hit iron off the tee, wedge some 12 feet behind the flag and clenched his fist when it dropped for birdie. That gave him a three-shot lead with two holes to play, and he kept it clean.

”I’m over the moon,” Knox said at the trophy presentation, where he picked up $1.4 million.

Knox grew up in Inverness and attended Jacksonville University in Florida. It took him five years to reach the PGA Tour, and he has been steadily improving. His only other close call was a four-man playoff in the 2014 Honda Classic that included McIlroy and was won by Russell Henley.