Australia's reigning Open Champion was one of many players to struggle at a tougher Los Angeles Country Club layout on Saturday.

Despite climbing from outright 10th to a tie for ninth, Smith's one-over-par 71 left him seven shots behind American co-leaders Rickie Fowler and Wyndham Clark entering the final round.

Smith at least finished his day on a high, draining a 20-foot birdie putt on the final hole after bogeys at 16 and 17.

“Lots of good in there. I don't think there was lots of bad, either. I think it was just the golf course was tough,” Smith said.

“The golf course is getting firmer and faster, as I expected, and going to take some really good play to get around even, and managed to hang in there for a while and get under par, and yeah, just a bit of a poor finish, I guess, the last five holes.”

Min Woo Lee went backwards on moving day like much of the field on a tougher LACC. PHOTO: Richard Heathcote/Getty Images.

But the Queenslander was put in the shade by playing partner and World No.1 Scottie Scheffler, who holed out for eagle at 17 and then followed Smith in with a long birdie putt on the 18th to move up to outright fourth at seven-under.

Smith can at least draw on his own recent history as he looks to make a charge in the final round.

He closed with an eight-under 64 in The Open at St Andrews last year, coming from four shots back to run down Rory McIlroy and claim a maiden major triumph.

The 29-year-old also had an equal-low final-round 65 to post his best PGA Championship finish last month.

“Geez, probably one of the best rounds of my life,” Smith said of what is needed on Sunday to win. “It's going to have to take at least five- or six-, probably even seven-under, I think. The golf course is getting tougher, but there's still lots of wedges out there. The leaders are there for a reason, as well. They're obviously playing really good golf.”

“Geez, probably one of the best rounds of my life. It's going to have to take at least five- or six-, probably even seven-under, I think. The golf course is getting tougher, but there's still lots of wedges out there." – Cam Smith.

Seven-time major winner Palmer holds the record for the greatest final-day comeback in U.S Open history, when he stormed home from seven shots back to win at Cherry Hills in 1960.

Fowler blew the chance to hold the outright third-round lead in LA after he three-putted the final hole for a bogey to slip back to 10-under with Clark.

Northern Irishman McIlroy (69) was outright third at nine-under as he chases a fifth major crown and his first since 2014.

Lee did it still tougher than countryman Smith on Saturday in California.

After carding the low round of the day on day two – a brilliant five-under 65 – to be in a tie for sixth, Lee struggled to a four-over 74 to slip back to 12th at two-under.

His American playing partner Sam Bennett had an even dirtier day, eventually signing for a nine-over 79 to tumble all the way to a tie for 47th.

Lee is bidding to join his two-time major winning sister Minjee Lee as a U.S Open champion and will be out in the seventh last group alongside Viktor Hovland, while Smith will follow in the next group with fellow major champion Hideki Matsuyama.

The final group heading off the 1st at LACC an hour later.