The world No.2 was hoping to maintain the momentum of three birdies late in his second round when he arrived on course for an early tee time on Saturday, seven shots off the pace.
After an embarrassing airswing in round two when his backswing clipped a tree, there was more grief in store when the Northern Irishman's ball on the second hole missed the fairway and nestled under a grassy clump.
The lie was worse than first thought with a discarded banana skin draping the ball, with McIlroy unable to remove it for fear of the ball moving, which would mean a one-stroke penalty.
The grand slam winner was almost bemused by the challenges the sandbelt course had provided him over three rounds, calling the latest a "double whammy".
"I feel like this is a week of firsts and in a lot of ways," McIlroy said.
"It's a loose impediment and it was resting on the ball so if I moved the banana peel, the ball would have moved so I just didn't even didn't even try.
"I mean, I shouldn't have been there in the first place, but yeah, it wasn't the best to start."
Showing his class, the reigning Masters champion immediately shook off Saturday's early blow to birdie the par-four third.
The sell-out crowd of more than 30,000 roared their approval through his back nine, with McIlroy adding another four birdies for a three-under 68, sitting at five-under for the tournament.Â
"I played well after that (second hole), sort of got a feel for it a little bit and especially I feel like I played the back nine well," he said.
"I just need to figure out how to how to make a few more birdies on the front."
He said he had struggled to build any momentum, with a number of putts failing to drop and the greens proving tricky.
"I feel like I haven't really got a lot of momentum at all over the past three days.
"When the putts hang on the lip ... it just feels a bit like the story of the week in a way.
"If I think back over the last three days, just like anyone else in this tournament, they'll tell you that they should be, you know, a lot better or a lot lower than they are.
"But, you know, maybe I turned it around with the last few holes there coming in, and all you need is that little bit of momentum to go your way, then you're off and running."
McIloy still clung to the slimmest hope of adding to his 2013 Australian Open crown, won at Royal Sydney with a late blitz overhauling Adam Scott, although Danish leader Rasmus Neergaard-Petersen at 14-under made that all but impossible.
"If everything comes together for me, I can shoot a pretty good one out there but whether that's good enough or not, I'm not sure," McIlroy said.
"I'll go out there and try my best tomorrow and try to shoot a low one and see where it leaves me."
