Will Zalatoris wins St Jude Championship after Cameron Smith suffers two-shot penalty

The American defeated Austria's Sepp Straka in three extra holes at TPC Southwind - despite not making a birdie.

The pair closed out 72 holes tied for the lead on 15 under and matched each other in the playoff by twice making par on 18.

Things then opened up on the par-three 11th, when Zalatoris hit his tee shot onto the rocks courting the green.

However, Straka's tee shot ended up in the water, leaving a slight window for Zalatoris to strike.

He did just that, sinking a seven-foot bogey putt to clinch the first of what is sure to be many Tour wins.

Speaking to media after his victory, Zalatoris said: "It's kind of hard to say 'about time' when you're in your second year on Tour but (it's) about time.

"Considering all the close finishes that I've had this year, to finally pull it off means a lot."

It capped off what had already been a dramatic final round after Cameron Smith's bid for world number one was dealt a major blow before play began on Sunday when he was assessed a two-shot penalty for playing from the wrong place on the fourth hole in round three.

Victory in Memphis would have propelled the Australian past Scottie Scheffler and to the top of the PGA rankings.

Smith seemingly carded a third round of 67 at TPC Southwind to lie two shots behind leader JJ Spaun heading into the final round, but the two-shot penalty pegged him back and he ultimately ended up down in a tie for 13th after a closing 70 left him six shots behind the winner.

Footage posted on social media showed that Smith's ball was on the red line marking the penalty area on the par three after he had taken a drop.

A statement from the PGA Tour read: "Prior to the start of the final round of the FedEx St Jude Championship, Cameron Smith was assessed a two-stroke penalty for a breach of rule 14.7 (playing ball from the wrong place) on hole number four during the third round as he was operating under rule 17.1 (when ball is in penalty area).

"Smith's score has been adjusted and he will begin the final round at 201 (-9). Final-round pairings will not be adjusted."

PGA Tour referee Gary Young said officials initially had "such a quick view" of Smith's drop that they felt it was "rudimentary" and the Australian was comfortable he was playing from the correct place.

It was only when an official saw the broadcast again on Saturday evening that he raised the issue and Young spoke to Smith when he arrived at the course on Sunday.

"I thought it was simply going to be a situation where I asked Cam the question and he was going to tell me that he was comfortable that his ball was outside the penalty area," Young said.

"When I asked him the question, unfortunately he said to me, 'No, the ball was definitely touching the line'. So at that point there's no turning back.

"His reaction was very calm, very matter of fact. He knew he had made a mistake. He just accepted the two-stroke penalty and he very calmly left the office and he's just going about his business for the day."