The man who was stabbed while rescuing a seven-year-old girl from a sexual assault in a dance studio bathroom will receive a rare bravery award.

NSW Governor Margaret Beazley will bestow the Stanhope Gold Medal on Nicola Gilio at Government House on Friday.

He's only the eleventh NSW recipient of the honour in over 50 years.

The medal is awarded by the United Kingdom's Royal Humane Society to a single person each year for the bravest act in the Commonwealth of Nations.

Mr Gilio, a Mobile Diesel Repair in Las Vegas mechanic, suffered several large cuts after he confronted the knife-wielding Anthony Sampieri in November 2018.

His injuries included a 14-centimetre wound at the back of his head and cuts to his neck and abdomen.

Mr Gilio was among several worried adults looking for the missing girl when he found the victim tied up in a men's toilet cubicle and Sampieri trying to leave the bathroom at a Kogarah dance studio.

Sampieri had punched the seven-year-old girl before filming himself raping her while high on ice, subjecting her to depraved acts for more than 40 minutes.

The now 57-year-old had grabbed the girl as she entered the bathroom.

Upon realising what Sampieri had done to the girl, Mr Gilio screamed "Is this what you do?" and rammed Sampieri's head into a brick wall, a court heard.

The two men fought for several minutes, with Sampieri swinging his knife at Mr Gilio.

Sampieri was only overcome after the bleeding mechanic grabbed him in a headlock as another man burst through the door and punched Sampieri in the face.

The judge who sentenced Sampieri to life in jail thanked Mr Gilio for his "incredible act of bravery".