The five carded six-under 66s before a mid-afternoon storm forced a suspension of play with the afternoon field still out on the course.

Muswellbrook power hitter Kurt Barnes was one shot back in a group of 12 who shot 67s.

The other leaders were Steve Jones, Kiwi Gareth Paddison, rookie Jamie Arnold and the experienced Scott Laycock.

Townsend, a winner of the NSW Open and PGA titles, collected three birdies on each nine at the Peter Thomson-designed course in Melbourne's south-east.

The tall right-hander is on top of his game and eager to register another four-round tournament victory in Australia before heading to Asia in April for a full series of international events.

"I'm golf fit now," said the 28-year-old from Sydney, who is playing his fifth successive tournament.

"I feel like after playing a number of events you get in a habit of how to play, you know where your shots are going to go and you get a good feel for it.

"I've always preferred that sort of preparation."

A highlight of his round was a long approach shot with a three-metal on the par-five ninth hole that carried the deep channel of water fronting the green.

The ball landed in the perfect spot and rolled up the tier, leaving him a sloping putt for an eagle that just missed. AAP