Australian Lucas Herbert has a four-shot lead after two rounds, but the focus was on the battle between Cameron Smith and playing partner Elvis Smylie.

Lucas Herbert shot an 8-under 63 at Victoria Golf Club to take the first-round lead at the Australian Open, with 2022 British Open champion Cameron Smith two strokes behind.

An unflappable Lucas Herbert led his home Australian Open at the halfway mark on Friday as fan favourite Cameron Smith tumbled down the leaderboard with a poor back nine at Kingston Heath.

Unheralded American Ryggs Johnston has joined home hope and halfway frontrunner Lucas Herbert in the Australian Open lead after a wet and wild third round.

Lucas Herbert surged into a four stroke lead at the Australian Open in Melbourne on Friday as his LIV Golf teammate Cameron Smith imploded on the back nine. While Herbert coped when the wind got up, Smith struggled.