Greg Norman withdrew from his home Australian PGA Championship after only two holes on Thursday due to a bout of food poisoning.
The 57-year-old former world number one bogeyed the first two of his opening round at the Palmer Coolum resort in southern Queensland state before deciding he could not continue.
"He's had a bad night," Australian PGA chief Brian Thorburn told reporters. "He tried to soldier on through the tournament but after a couple of holes it just wasn't possible for him.
"He's under medical attention at the moment."
Norman was one of the A$1.25 million tournament's main drawcards along with fellow former British Open winner Darren Clarke and 2006 US Open winner Geoff Ogilvy.