Canberra golfer Matt Millar slipped on the back nine to start his Australian Open campaign, dropping shots to finish his opening round at one-over par.

Millar had a wild end to his first round and struggled for consistency as the wind and wet weather hit the course at The Lakes in Sydney.

The 42-year-old was one-under par after nailing a birdie putt on the ninth, but then he hit trouble on a rollercoaster five-hole stretch.

He double-bogeyed the 14th, bogeyed the 12th and 16th and then made back some ground with birdies on the 13th and the 15th. Millar was hoping to target his best Australian Open result in almost 20 years.