Adam Scott shares the clubhouse lead after shooting a four-under-par 67 to open his Australian Masters title defence at Royal Melbourne.

But little-known Victorian Anthony Brown tops the leaderboard after making a blazing start to be five-under through just seven holes, opening with birdie, eagle, birdie.

Coming off his Australian PGA Championship victory on Sunday, world No.2 Scott is tied with young German Max Kieffer (67).

Scott, the US Masters champion, briefly held the lead outright after making four consecutive birdies but a bogey on his second last hole saw him slip back.

Victorian Jarrod Lyle has made an emotional return to professional tournament golf after recently winning a second battle with leukaemia.

Watched by a large galley, Lyle is one-under after three holes.

Kieffer, 23, is making his first trip to Australia and his quest is being assisted by his Australian caddy Graeme Heinrich.

American world No.8 Matt Kuchar has shot an even-par 71.