Marc Leishman was not going to cave at Augusta National again. He point-blank refused.

A previous monumental Masters collapse came to mind when he opened the second round with three straight birdies, announcing himself a serious contender for the green jacket.

He'd done the same in 2014 only to drop 10 shots in his next 12 holes, sign for a 79, and miss the cut by a shot.

This time he resolved to stay aggressive but level-headed.

A few hours later a five-under 67 left him tied fourth at the half-way mark of the year's first major.

"There's no doubt I learned a lot from 2014," Leishman said.

"It's about finding that mix of aggressive but not reckless.

"I couldn't be more excited. This is why I came here. This is the position I wanted to be in."

That position is two shots behind leader Justin Rose, who needed to birdie three of his last six holes just to shoot even-par 72.

The first-round leader's overnight four-shot cushion is just one over Americans Will Zalatoris (68) and Brian Harman (69).

Also lurking ominously is three-time major winner and in-form 2015 Masters champion Jordan Spieth, who posted a 68 to join Leishman at five under.

Leishman was the first-round leader in 2013 before finishing fourth behind Australia's lone Masters winner Adam Scott and was second through 36 holes in 2018 before fading to ninth.

He has learned from those experiences also.

"The course can change overnight either way, from hard to soft, soft to hard," Leishman said.

"So the practice putting green tomorrow is going to be important, getting the speed of the greens... I learned you have to take each day as it comes."

Leishman is not be the only Australian with a chance.

Cameron Smith and Matt Jones are just five and six shots off the lead in a share of 13th and 17th place respectively.

The 2020 runner-up Smith carded a four-under 68 to keep his goal of going one better than his historic, four sub-70 rounds effort last November.

It could have been so much better as he reached five under with an eagle on the par-5 13th but leaked three shots over the next two holes.

A "rubbish" double bogey on the 15th after finding water still smarting.

"I'm quite frustrated... it was just rubbish, to be honest," Smith said.

"I played some really good golf... I hit a lot of good shots coming in and just didn't really get anything out of it."

Jones rocketed into contention with a three-under 69, one of only 20 players under par in his first Masters appearance since 2014.

Scott (73) made the cut on the number at three over but would need a massive weekend to have any hope of contending again.

That's more than can be said for fellow former world No.1 Jason Day, who missed the cut for the second straight year after rounds of 74 and 76.