Rory McIlroy was pipped to the BMW Championship title in St Louis by Wyndham Clark after his final-round fightback fell short.

The back-to-back Masters champion started the final round five shots behind overnight leader Clark but was level after 15 holes.

But while McIlroy bogeyed the 17th, Clark maintained his composure to birdie the 16th, 17th and 18th holes to wrest back control and finish the tournament on 17 under par.

The two-time US Open champion ended the tournament three shots clear of Patrick Cantlay, who edged McIlroy for second.

It moves Clark up to third in the FedExCup Rankings after he won his third PGA Tour title of the season.

McIlroy had multiple chances to take the lead outright but he was not able to get a putt to drop before ultimately making a bogey six on hole 17 to end his challenge.

“A big improvement on last week,” McIlroy said on Sky Sports Golf. “I don’t think I can be too disappointed, I’m probably not playing well enough to be disappointed I didn’t win.

“I had my chances on the back nine. I started to hit some good shots. I hit a lot of good putts that didn’t go in.

“Wyndham stepped up when he needed to. The birdie on 16 was huge. The way he played the last three holes, he showed a lot of character there.”

McIlroy birdied the opening hole at Bellerive Country Club, while Clark three-putted to bogey the 415-yard par four.

McIlroy dropped shots at the fourth and seventh but responded with back-to-back birdies before the turn.

Another gain at the 11th put him in a tie for the lead, but he could not get a birdie putt to drop on the next five holes before he found sand twice on the 17th to end his challenge.

Clark was three over for the day heading to the 16th tee, but a 16-foot putt on that hole earned him his first birdie and he followed it by sinking efforts from 13 and 17 feet on the next two greens to get over the line in style.

Cantlay’s closing 68 saw him finish a shot ahead of McIlroy, with fellow Americans Gary Woodland, Collin Morikawa and Chris Gotterup in a tie for fourth on 12 under, and Scotland’s Robert MacIntyre finishing in a tie for seventh after a brilliant closing 65.