Marc Leishman was convinced it was going in the water; Cameron Smith thought it was so far left as to not get wet.

Tied for the lead of the Australian PGA Championship for the first and only time all day, the tournament favourites and World Cup teammates stepped onto the 15th tee for the 105th hole they had played together in the space of two weeks with their fate still undecided.

Sleeping on a three-shot lead overnight, Smith’s first shot of the day landed in a bush and necessitated a penalty drop and by the fourth hole, after a Leishman chip-in, the hunted had all of a sudden became the hunter.

By the time the pair made the turn in what increasingly became a tournament in two, Leishman had established a two-shot lead, an advantage he carried through until the 13th hole.

Smith’s birdie reduced the deficit to one and then a Leishman putt for par that horseshoed out of the hole at 14 swung the momentum the way of the defending champion, the Victorian challenger unable to counter.

Not only did Smith’s tee shot at 15 bounce forward off a grate to nestle in the left rough, his second finished alongside signage on the 16th tee, a local rule allowing Smith the opportunity to drop in front of the sign on the tee box and a better angle to the hole without penalty.

Deadly with wedge in hand, Smith played his pitch to inside a metre and made the putt for birdie, leaving Leishman to rue another major title on home soil that had slipped through his grasp.

“In Boston a couple years ago I was leading by a couple going into the back-9 and lost that, that one really hurt, but this is probably equally if not more than that,” said a clearly disappointed Leishman.

“I've always said to Audrey, if I have a bad day, just give me 10 minutes after the round and I'll be good.

“This one might take 20.

“I had chances and I actually hit a few pretty good putts.  I hit a really good putt on 15 I thought was in and didn't go in. Hit a good putt on 14, the horseshoe.

“I gave it my best crack and couldn't quite get over the line.  That's golf sometimes.”

When Smith was granted a free drop onto the 16th tee Leishman moved across to check with the rules official that he was proceeding in the correct manner, clearly aware of the significance of the ruling in the context of their duel.

“I wasn't annoyed at all, I was just checking,” Leishman explained.

“Being a competitor, I wanted to make sure if he was dropping on the tee that's where he was meant to drop it, not in the rough.

“No hard feelings at all there, I just wanted to make sure he was doing the right thing.

“I’m definitely disappointed at the moment, but you're always happy for Cam. We had a good fight out there.

“At the end of the day, I did want to win. Gave it my best and just didn't make it. He played good and credit to him.”

Knowing how desperately his good mate is to win one of Australian golf’s major titles, Smith conceded as he sat behind the Joe Kirkwood Cup that he couldn’t help but feel sorry to stand in Leishman’s way.

“It’s always hard going up against a mate and trying to win a golf tournament,” said the first player to successfully defend his Australian PGA title since Robert Allenby in 2001.

“I’ve been in this situation before and had it happen to me as well.

“It’s a weird one but I’m sure we’ll have a beer when I see him next and we’ll be back to being mates.”