Adam Scott says his heartbreaking missed opportunities at the Open Championship over the years have been the inspiration behind his mammoth fightback from potential disaster at St Andrews.

The Queenslander was staring down a horror opening round on Thursday at the famed Old Course when he was four-over-par through six holes. But the former world No.1 rallied with four birdies for an even-par 72, which set up a scintillating seven-under 65 in round two.

At seven-under-par, Scott sits six shots back of fellow Australian Cameron Smith. Smith leads Cameron Young (69) at 11 under, while four-time Major winner Rory McIlroy (68) and Viktor Hovland (66) were third at 10 under. Two-time Major champion Dustin Johnson (67) was nine under.

Scott, who turns 42 on Saturday, has not recorded a bogey in 30 holes. On Friday, he bagged three front nine birdies before adding four more on the back side.

Scott’s best ever round from 22 years of playing the Open catapulted him up its famous gold leaderboard and back into contention. Aside from the fact this week is the 150th edition of golf’s oldest Major, Scott said his crushing collapses at the 2012, 2013 and 2015 Opens added motivation.

In 2012 at Royal Lytham, Scott lead by four shots with four holes to play only to drop a bogey on each hole. In both the 2013 and 2015 Opens – the latter being the last time the championship was held at St Andrews – Scott held at least a share of the lead on the Sunday back nine only to fade away.

“You don’t need much extra motivation at an Open Championship, but anytime I think about letting one slip through my hands, it hurts,” said Scott, who finished second in 2012, tied third in 2013 and tied 10th in 2015.

“It would be exciting if I shot a really great round tomorrow and teed off (Sunday) with a legitimate feeling that I’m in contention, not only for the fact that I haven’t really been in that position for a Major for a little while, but also for the fact that I’ve had one on this jug, I feel like, and I’d like to put two on.”

Scott, the 2013 Masters winner, said he would have to shoot something in the mid 60s at least in round three to be within striking distance for the final round.

“I (have) to get into double digits under par to even have a chance; I’m probably going to be a fair way back at the end of today, I’d think. But I’m on my way. So it’s kind of (time to) attack, if you can do that around here.”

Min Woo Lee’s second consecutive 69 put him at six under, tied with fellow Australian Lucas Herbert (68). Brad Kennedy (72) was four under while Anthony Quayle (15 holes) was two under. Jason Scrivener (71) was one under.

Matt Griffin (two over), Marc Leishman (six over), Dimi Papadatos (seven over) and Jed Morgan (11 over) all missed the even-par cut.