Smith confirmed his status as one of golf's premier players, finishing outright fourth behind American winner Wyndham Clark at Los Angeles Country Club.

At six-under, Smith ended up four shots adrift of Clark, who closed with a tenacious even-par 70 to hold off Rory McIlroy (69) by a shot.

World No.1 Scottie Scheffler produced a final-round 69 to finish outright third.

Smith's exciting countryman Min Woo Lee also enhanced his reputation as a potential major winner-in-waiting with a tie for fifth.

While never seriously in contention on Sunday, Smith and Lee showcased their class with gritty three-under-par final-round 67s as many of the game's big guns struggled in the typically gruelling U.S Open conditions.

Smith roared home with three back-nine birdies while Lee produced a steely bogey-free round under the intense pressure of the most demanding of golf's four annual major championships.

Min Woo Lee continued his impressive start to his major championship career at LACC. PHOTO: Sean M. Haffey/Getty Images.

"For me, I feel like the game has been trending in the right direction," Smith said. "This is kind of a big tick of the box, I think. Obviously a world-class field, world-class venue, and it got really tough on the weekend, as well.

"So the game is feeling really good, and just probably a little bit of confidence."

Smith and Lee were fresh off their best PGA Championship finishes and were the only two Australians to make the cut.

Smith's renaissance is especially timely, little more than a month before he heads to Royal Liverpool trying to defend his title after last year's memorable victory at the landmark 150th Open Championship at St Andrews.

After making a sluggish start to the season playing a lighter schedule on the LIV Golf breakaway circuit, the 29-year-old is warming to the task nicely.

He closed with a course-record nine-under 62 to force a play-off at LIV Golf Tulsa last month before recording his first top-10 finish at a PGA Championship the following week in New York.

“It feels right there," Smith said when asked to compare his game to last year. "If anything, I think the driver feels better than what it did last year, and the irons and the short game, I think they're right there. I think I'm a better player than what I was last year.”

"For me, I feel like the game has been trending in the right direction. This is kind of a big tick of the box, I think. Obviously a world-class field, world-class venue, and it got really tough on the weekend, as well." – Cam Smith.

Lee is also trending upwards, the Perth prodigy's fifth an impressive encore to his tie for 18th at Oak Hill and continues the strong start to his major championship career that has already yielded five top-30 finishes.

If not for a horror six-over stretch on Saturday, the 24-year-old would have been right in the mix to contend for the title on Sunday, and potentially become the second member of his family to win a U.S Open after sister Minjee won the U.S Women's Open last year.

“It's amazing. Again, I don't get too many top results that often, as much as the top players, so it's really nice to do it at a major and do it at a U.S. Open," Lee said.

“Yesterday I just put too much pressure on myself and was actually pretty nervous in a way. My practice was so good that I kind of put a little bit of pressure on myself, and today's was a little different.

"The pre-round was a little sketchy and not the best, and then you just go out there with a good mindset. Played amazing today, bogey-free. I don't have many bogey-free rounds ever so it's nice to do it at a major."