Updated March 13, 2017 07:37:41

Actor Samuel Johnson has taken out the prize at this year's Birdman Rally in Melbourne, despite casting aside an apparatus made of bras and diving head first into the Yarra.

Crowds gathered as competitors leapt from a platform to try to fly across the river as part of the annual Moomba Festival event.

Fifteen competitors donned costumes and flying apparatus to try to make it across the Yarra, before inevitably plunging into its muddy depths.

Entrants were judged on how many metres they flew, but could boost their scores based on how much money they raised for a chosen charity ahead of the event.

Johnson raised more than $20,000 for cancer charity Love Your Sister, established in 2013 after his sister was diagnosed with cancer for the third time.

The actor, who has starred in shows including Molly and The Secret Life Of Us, quit his profession last year, in order to devote his time to raising $10 million for cancer research, saying he could not 'pretend on telly' while families were suffering.

"I came just hoping to etch my charity into the annals of Australia's cultural iconography but it turns out we might have won the Birdman Rally as well, so I'm flipping beside myself," he said.

Mr Johnson said his "classic face plant" into the Yarra hurt but it "was good pain".

"I just had to throw caution to the wind and just commit. I'm scared of heights there's so many people here you don't want to let them down, so I had to do something stupid. I don't know if I lose points for abandoning my boob-chute."

Upon receiving the award, Mr Johnson told the crowd the prize would be shared among all the charities who were represented in the rally.

Life saving crews and divers waited close by to help competitors out of the water.

Topics: human-interest, arts-and-entertainment, events, charities, community-and-society, charities-and-community-organisations, vic, melbourne-3000

First posted March 12, 2017 13:49:16