Strike while the iron’s hot.

It’s been Adam Scott’s approach since winning April’s US Masters and he’s poised to pounce again after a strong start to his Australian Masters defence.

The world No.2 used a mid-round run of four birdies to build a four-under-par 67 at Royal Melbourne on Thursday.

It gave him a share of second, two behind late-blooming 29-year-old South Australian left-hander Nick Cullen.

Cullen is the twin brother of cricketer Dan, an off-spin bowler who has represented Australia at Test and one-day level.

Nick, who turned professional only four years ago after previously doubting he had the necessary talent, has begun carving his own slice of sporting fame.

He posted his maiden professional win in last year’s Indonesia Open and won the Queensland Open three months ago.

On Thursday, he surged to the outright lead with a purple patch from holes 11 to 13, first chipping in for eagle then notching two birdies to climb from two-under to six-under.

He briefly reached seven-under before finishing with a bogey.

Earlier, Scott headed to the practice range straight after his round, but was content with his score.

While he missed some early birdie chances and tailed off late, after reaching five-under with five holes to play, he was pleased that he capitalised on some fine mid-round ball striking.

He birdied holes one to four, having started on the 11th.

“You just need a few good holes to have a good score and I was patient,” Scott said.

“I was trying not to get frustrated because I felt like I had left some opportunities out there.

“That is all you need to have a good round, a hot 20 minutes.”

Scott, who won last week’s Australian PGA on the Gold Coast, said since his breakthrough US Masters victory, he had been determined to keep riding the momentum.

“My big thing after winning the Masters was to keep my head down and practise hard and use the confidence of winning a big tournament,” he said.

“I am trying to keep my momentum going and strike while the iron’s hot.”

German Max Kieffer shared second place, while Zimbabwe’s Brendon De Jonge was among a large group on three under.

Cancer survivor Jarrod Lyle shot 72 in his emotional return after 20 months out of tournament golf.

American world No.8 Matt Kuchar and big-name Australians Geoff Ogilvy and Marc Leishman were all even with the card, but veterans Nick O’Hern (78) and Craig Parry (76) were well off the pace.