Marc Leishman says his heartbreaking playoff loss at the 2015 Open Championship still haunts him, but he’s determined to vanquish those demons as golf’s oldest Major returns to the famed Old Course at St Andrews.

Fans will remember Leishman copping a cruel break when his ball settled in a fairway divot on the first hole of a four-hole aggregate playoff at the 2015 Open at St Andrews. He never recovered and American Zach Johnson hoisted the Open’s Claret Jug, while Leishman and Louis Oosthuizen were playoff losers sharing second place.

Leishman, though, says the damage was done well before going into a playoff. He had racked up seven birdies in 12 holes during the final round and held a one-shot lead through 15 holes. But disaster struck at St Andrews’ par-4 16th when he made perhaps the biggest error of his career so far.

“If I could have one shot over in my career, it would be the second shot into 16,” Leishman tells Australian Golf Digest in Scotland. “I pulled the shot left. There was out-of-bounds right and I didn’t commit and pulled it left. If I could have that over again, I might have the Claret Jug in my trophy case. I played a really good bunker shot straight after, but I missed a five footer for par, which I misread. I also remember the (missed birdie) putt on 18, which was basically to win and I misread that too. I think about that one a bit.”

Leishman posted the clubhouse lead but Oosthuizen and eventual winner Johnson later forced a three-man playoff. The tie for second remains Leishman’s best finish at a Major. Leishman, now 38, calls 2015 “the one that got away”. Victory would have been sweet for the fact only three months prior to that Open, Leishman nearly lost wife Audrey to a freak case of toxic shock that was triggered by sepsis.

“It’s something I think about every now and then, with how close I was to winning,” says Leishman. “It was a week of what could’ve been. But I usually cheer up when I think about how lucky I was to be on a golf course. When doctors thought Audrey might not make it, I was going to quit golf to take care of the kids. It was a very weird, or bittersweet week for me.”

The 2015 Open was memorable for Leishman’s caddie, Matt Kelly (left) who found out he was going to be a father the night before the final round.

Fast forward to this year and Leishman is coming off his best US Open result, a tie for 14th at Brookline last month. He feels ready to contend for the Claret Jug this week.

“I feel like I’ve got some unfinished business here,” the Warrnambool native says. “I learned a lot in 2015; not just about golf but how I handled myself and I feel that could help me this week. I feel like I have added motivation, but I know when you feel like that you have to manage your aggression and anger.”

Leishman has added five more PGA Tour wins since 2015, for a total of six, and he’s also had a stint in the world’s top 20.

“I’m a more complete player now,” he says. “But I need to play as good as I have when I’ve won regular PGA Tour events by several shots, because in a Major that margin of victory is the equivalent of winning by one, that’s how tough Majors are. Particularly an Open at St Andrews, it’s like the Masters. It’s anticipated and we’ve thought about it for a long time.”

Leishman’s fellow Australian, former world No.1 Scott, also laments a missed opportunity at the 2015 Open.

Scott had charged out in 31 on the first nine of the final round and he took a share of the lead with a birdie at the seventh. But he collapsed on the back nine, notably with a bogey at the par-5 14th, when his 1-foot putt for par missed the hole, as well as a double bogey-6 at the 18th.

That was a bitter pill to swallow, absolutely,” Scott told New Zealand Golf Digest. “I was one shot back with four to play and Zach was group in front. It was all there in front of me and I had being putting my hand up at the Open for a few years to that point. Then 14 happened and then I hit it out of bounds on 18. It was a really disappointing.”

Still, Scott says he has as much positivity and intensity at this Open compared to 2015. Scott is ranked No.42 in the world off the back of a solid tie with Leishman for 14th at the US Open, as well as four top-10s across the PGA Tour and DP World Tour this year. He’s hungry.

“It’s the last hurrah for the Majors this year and it’s the big one for sure,” he says. “I hope this isn’t the case but it could be my last run at an Open at St Andrews. I have to leave it all out there this week, and hopefully I can get myself into a similar headspace that I had at the US Open where it’s like you’re playing do-or-die golf. I want it.”

Scott and Leishman are among an 11-strong Australian contingent for the 150th Open. World No.6 Cam Smith headlines the pack, followed by Lucas Herbert, Min Woo Lee, Anthony Quayle, Jason Scrivener, Dimi Papadatos, Jed Morgan, Brad Kennedy and Matt Griffin.