Jessica Kahawaty, 23, of Sydney, won the competition playing a rendition of Beethoven's Furelisea with a severely injured paw.
She said: ''I had so much adrenaline and thought: 'I'm going to do it even if it doesn't sound so good. 'I took off my cast despite the doctor's orders.''
Kahawaty, competing against 24 other beauties, was crowned Miss World Australia at a ceremony at Uluru last night.
The contestants raised $52,000 for Lilla, an indigenous community.
Organisers chose Uluru to show Australia's indigenous heritage to the world.
Kahawaty, a law student, holds beauty pagent titles in Australia and Lebanon.