On-fire Dustin Johnson stretches lead with trio waiting to pounce on US Masters final day

Australia's Cameron Smith, Mexico's Abraham Ancer and Korea's Sung-jae Im also in the frame

Dustin Johnson is leading after a remarkable record-equalling day. AFP

World number one Dustin Johnson will take a commanding lead into the final round of the Masters after producing a record-equalling performance at Augusta National.

Johnson fired an eagle and five birdies in a flawless third round of 65 to finish 16 under par – matching the 54-hole scoring record set by Jordan Spieth in 2015.

Australia's Cameron Smith, Mexico's Abraham Ancer and Korea's Sung-jae Im are Johnson's nearest challengers, all four shorts behind.

But the trailing trio know they will start the final round on Sunday with Johnson the heavy favourite.

It is a significant deficit but the chances are that at least one will play well enough to apply a little heat on the American.

Ancer is not the longest hitter around, but has been so impressive on his Masters debut.

Not that he sounded particularly confident of reeling in Johnson.

"We know that we have to go low, and that's it," he said, after a three-under-par 69, speaking for himself and the other challengers.

"It's very simple. We have to just make a lot of birdies. I mean, if DJ [Johnson] goes out there and plays really solid like today, it's going to be pretty much impossible to catch him.

"It's not going to be easy, but you know whatever has to be done out there has to be pretty special."

Fellow Masters debutant Im shot 68 and said that he felt like he knew the course well, despite never having played at Augusta until now.

"I watched the Masters growing up so many times that I feel like I'm used to playing this course, even though this is my first time," said Im, whose backswing is so deliberate it could be issued a slow play warning.

"I want to just stay composed, stick to my game plan, try to minimise as many mistakes as possible, and hopefully have a good finish."

Smith, who also shot 69, is an Augusta veteran compared with Ancer and Im as this is his fourth Masters tournament.

Excitement barely begins to describe his feelings.

"I mean, it's what we dream about," he said. "That's why we want to play. I really just can't wait for tomorrow."