Rules whizz Rory McIlroy left his Aussie playing partners red-faced at the Mastercard Masters in Melbourne.
The teenager, 18, was quizzed by Aaron Baddley and John Senden about taking a two club length drop from a sprinkler head as he opened with a two under par 70 to share 10th place behind Robert Allenby.
But US based Aussies ended up looking embarrassed as referee Andrew Langford-Jones confirmed that the Holywood hotshot was perfectly entitled to relief under a local rule at Huntingdale.
Langford-Jones said: "It's a problem we always have and that is we issue a supplementary local rules sheet to all players but they just don't read it.
"Rory's actions were correct and it's a local rule that's in effect on a lot of courses like Huntingdale and also including Carnoustie where the British Open was held this year.
"It's just that Aaron and John are so used to competing in the US where you don't get the conditions we have here at Huntingdale."
McIlroy chipped dead to secure his par on the 11th after previous birdies at the fifth, seventh and eighth.
He bogeyed the ninth after a poor drive into trees before paring every hole on he way home.
Happy with his start, McIlroy said: "I feel as though I did okay out there today as it was tough out there and it got very windy towards the end of the round, so two under par is pretty good.
"I made a lot of good up and downs to hang in there and I finished in the top-15 so I am pretty happy with how the day went.
"I played alongside Aaron and matched his score of two under, and I finished ahead of John who's defending the Australian Open in a couple of weeks, so that's not too bad."
Rookie McIlroy missed the cut in last week's Hong Kong Open but believes he is ready to challenge for his first title this week.
He said: "If I played today like I did last Friday in Hong Kong and with the mindset I had last week, then I would have shot 74 or 75.
"But I was really pleased with my efforts today and I'm sure that I can only improve from today's round."
Damien McGrane hit a level par 72 that featured three birdies and three bogeys.
Two-time Mastercard Masters winner Allenby leads by a shot on five under par from England's Peter Baker and Sweden's Fredrik Andersson Hed.