Manley's approach on the fourth went into a greenside bunker, and his third shot went off the back of the green. When he chipped back on, his shot rolled off the front of the green and into a gully.
From there, it took him four attempts to get the ball back on the green it kept rolling back down to his feet before he three-putted for the 11. He went then from second to a tie for 15th.
Manley, who shot an opening-round 67 to be among the first-round leaders and shot 72 on Friday, reacquired his European Tour card for next year at last week's qualifying tournament in Spain, then made a rushed trip to Australia.
It's his first time playing at Royal Melbourne he came here in 2005 in an attempt to get into a tournament, but never got in as a reserve.
The 346th-ranked Manley intended to play in the team event for Wales, but his scheduled partner, Jamie Donaldson, withdrew with a back injury. That forced Manley to play as one of eight individuals in the 60-player field.