Smith settled for equal third spot behind triumphant World No.1 Scottie Scheffler and a roaring Rory McIlroy, after closing with a luckless one-over-par 73.

The Queenslander must be wondering what might have been.

After slashing Scheffler's overnight lead to just one stroke with two superb birdies to open the final round, Smith's Masters dream began to slip away in an extraordinary twist on the 3rd hole.

After driving into the trees left, Scheffler was given relief from an interfering scoreboard, his second favourable drop in four holes after escaping with a miracle bogey up the last on Saturday.

Scheffler left his ensuing pitch shot short and watched his ball tumble back down the hill.

Smith and the champion Scottie Scheffler during the final round, the Queenslander recording another top-5 finish at Augusta. PHOTO: David Cannon/Getty Images.

Staring a bogey in the face as Smith threatened to seize the lead, the Texan instead chipped in for a most improbable birdie.

After also leaving his approach short, Smith was unable to save par from the same position as Scheffler's hole-out, suddenly leaving The Players champion three shots behind again.

He never recovered.

Another bogey on the par-3 4th hole, after taking an aggressive line off the tee and finding the bunker, had Smith trailing by four shots.

Both players birdied the seventh as Scheffler moved to 11-under and assumed control.

Runner-up to Dustin Johnson in the rescheduled November Masters in 2020, Smith seemed set for at least another second after making a brilliant birdie on the par-4 11th, one of Augusta's most demanding holes.

Instead, the 28-year-old's tee shot into the water and racked up a heartbreaking triple-bogey six on the 12th hole as Amen Corner claimed yet another victim.

"Just a really bad swing at the wrong time. It was actually a really good number. It was a really nice 9-iron. Wasn't even trying to go near that pin, and, yeah, just a really poor swing," Smith said of the tee shot on 12.

"I feel like I hung in there tough a couple of days. Friday, I feel it probably could have got away from me a little bit, and then again this afternoon, so it was good. My game feels really good. I feel really confident in my game. I feel really comfortable around here. I love this place. I'll be back here next year and trying to put up another one."

Smith rebounded gamely with successive birdies on 15 and 16 to secure a third top-five finish at the season's first major.

Countryman Min Woo Lee had a more memorable day, tying the Masters front-nine record course en route to a top-15 finish on debut.

Lee eagled the par-5 2nd, then reeled off four straight birdies to surge to reach the turn in 30 shots.

At two under, the 23-year-old was briefly holding down fourth spot before eventually signing for a two-under round of 70.

A two-over 72-hole total left the younger brother of major-winning LPGA Tour star Minjee Lee in a tie for 14th alongside the likes of defending champion Hideki Matsuyama and former World No.1 Lee Westwood.

Marc Leishman (74) tied for 30th at five-over, Cam Davis (73) finished 46th at 12-over, while former champion Adam Scott (74) shared 48th spot at 14-over after making the cut for a 13th straight year.