Moseley stood at 16-under through 10 holes when storms rolled into the area. Aaron Baddeley was alone in second at minus-14.
Moseley had a one-shot lead to start the third round and was soon joined atop the leaderboard by Baddeley, who had an eagle at the fourth to grab a share of the lead.
Baddeley faltered with a bogey just before the third round was suspended while Moseley pulled away with back-to-back birdies from the fourth and another birdie at the eighth.
Peter Lonard, who shared the opening-round lead with Moseley, birdied the second and the fourth to move to 13-under. Adam Le Vesconte and Nick O'Hern are two shots further back at 11-under.
Adam Scott had three birdies on his round before play was called. The 22-year-old is alone in sixth at 10-under par through 11 holes.
Greg Norman bogeyed the first hole at Hyatt Coolum Resort. He parred the next eight holes before catching fire on the inward half with three consecutive birdies starting at the par-4 10th. Norman added a birdie at the 14th to move into a tie for seventh alongside Greg Chalmers and Tony Carolan at 8-under.
Stuart Appleby was at 7-under through 14 holes. He was joined by Cameron Percy, Brad King and Greg Turner nine shots off the pace.
Full-field scores from the Australian PGA Championship