Cameron Smith has pulled away from the field today at Murray Downs after a 5-under 66, to secure a two shot lead heading into the final round of the Ford NSW Open.

While it has been Smith versus Ripper GC teammate Lucas Herbert all week, after a frustrating 1-over 72 from Herbert today, Smith will be joined by two new playing partners for Sunday's round.

Hunter Valley's Corey Lamb and 41-year-old Alexander Simpson, who plays much of his golf on the adidas Pro-Am series, will stroll the fairways with major-champion Smith tomorrow.

Lamb is Smith's closest challenger at 13-under, the 23-year-old fired a 67 today to continue his quest for a maiden Challenger PGA Tour of Australasia victory.

While tied third with Herbert and Kiwi Josh Geary at 11-under, it is Simpson who makes up the final group after a steady 3-under 68 today to continue his magical week thus far.

With his biggest pay-day in professional golf currently $3600, Simpson is in uncharted waters. Having already demonstrated he has the game to match it some of the world's best this week, one more low one is far from out of the question.

The penultimate grouping on Sunday consists of Herbert and Geary, alongside former NSW Open champion Harrison Crowe, who carded a 3-under 68 today.

While Herbert held a two-shot overnight lead, Smith was able to flip the script early, playing his first five holes in 4-under. The highlight an eagle on the par-5 fourth, his second knocked in close.

Three more birdies on the back nine for Smith, while Herbert made two frustrating doubles, meant his lead was continuing to stretch.

After looking like his game was on cruise control for 16 holes today, Smith tugged an iron off 17 tee and found the fairway bunker left. As if to rub salt into the wound, an overhanging tree meant Smith's backswing was impeded, and in the blink of an eye the 2022 Open Champion walked off with a double bogey of his own, just letting the rest of the field back in slightly.

"It was really a shame to not finish as good as I wanted to," said Smith. "Did what I needed to do today and on 17 there it was just, I don't know. I don't even know what it was to be honest. It's all a blur."

It was the only mistake Smith made all day, and while it could have been more comfortable lead, the Queenslander knows any 54-hole lead is a blessing, considering he will have the rest of the field hunting him, including Herbert.

"Leading into the last day is where you want to be, you want to be there thereabouts. I just need to do more of the same as what I did today," he said.

"With Herbie having the day he did today, I expect that he's probably going to come out with a good one tomorrow.

One of the players out to hunt down Smith, and not daunted by the prospect, is his Sunday playing partner Lamb.

"I want to be the best, and you've got to play with the best to be the best," Lamb said of his Sunday pairing.

Hunting his first Tour win, Lamb has come close, with back-to-back runner-up finishes at the last two Webex Players Series South Australia events.

Having taken out the NSW Amateur and Queensland Amateur in consecutive weeks in his junior years, Lamb has a winning mentality, and knows it is only a matter of time out here.

"I think if I can get off to a solid start, it'll give me a lot of confidence to go through to just play good golf," he said.

"I've played well the last three rounds, and I feel like I've sort of left a few out there.

"The last two days I could have went a bit lower, so hopefully they can all drop tomorrow and I have a perfect round."