Cameron Smith has become the first player to win successive Australian PGA Championships since Robert Allenby in 2001 after launching a stunning late comeback in the final round at RACV Royal Pines Resort.

A wayward drive on the first hole and a second bogey on the par-4 fourth saw Smith’s three-shot overnight lead quickly evaporate as close friend Marc Leishman took control of the tournament, chipping in on the fourth hole to assume the role of front-runner.

As Leishman made the turn in 4-under par Smith was fighting off nerves to be 1-over before three birdies in the space of four holes midway through the back nine turned the tournament on its head.

Cameron Smith celebrates winning on day four of the 2018 Australian PGA Championship at Royal Pines Resort on December 2, 2018 in Gold Coast, Australia. (Photo by Chris Hyde/Getty Images)

The pair both made birdie at the par-5 12th as Leishman maintained a two-shot advantage, a lead Smith was able to halve with a birdie three at the par-4 13th.

The first stroke of ill luck to befall Leishman occurred on the 14th when his putt for par did a complete lap of the hole and stayed out but it was at the par-5 15th where the golf gods truly conspired against him.

A wild drive by Smith appeared destined for the lake on the left side of the fairway only to bounce off a rock and forward into the left rough. His second shot flared out to the right and came to rest just behind the signage on the par-3 16th tee.

He was able to take relief from the signage and used his world-class short game to play a pitch shot to inside a metre, the successful birdie putt putting the 25-year-old one shot in front with three holes to play.

A Leishman bogey at the 16th doubled Smith’s lead and when the pair shared pars on the 17th the defending champion put one hand back on the trophy, reclaiming possession with a par at the last.

Smith’s former Queensland Boys teammate Jake McLeod also endured a nervous afternoon before being declared the winner of the ISPS HANDA PGA Tour of Australasia Order of Merit which brings with it a one-year exemption onto the European Tour and entry into two World Golf Championship events.