As a judoka, Tony Clarke is used to the odd dirty trick.
And as a blind judoka, he's suffered some of the worst ones in the book - including having sighted opponents tip-toe around him for a surprise crash tackle.
But there was nothing more painful for the five-time Paralympian than being told he could not compete at the Beijing Olympics simply because he can't see.
He certainly felt he was good enough.
Clarke, 47, has been No.3 in Australia before and has won national titles five times competing against his sighted counterparts.
Judges banned him from Olympic qualifiers in 2005, saying his disability could affect how other judokas and referees treated him.
"They liked me until I got too good," said Clarke.
"The discrimination is so blatant it's unbelievable."
A civil rights campaigner as well as a motivational speaker, Clarke fought the ruling.
A two-year court battle ensued, affecting his professional and personal life, as well as his finances, before he finally threw in the towel last year.
"It was a crucial case not just for me, but for all disabled people," he said.
"In hindsight I wish I'd continued, but it was better just to cut your losses."
The battle even cost him his friendship with his then-coach of 14 years as the case took its toll.
"I gave up judo because of it for a while, I'd lost all my confidence," he said.
"I'm a motivational speaker, I tell people it's an equal opportunity sport, you can go anywhere with it, and then I realise I've been patronised for the last 20 years."
Australia's lone judoka at the Beijing Paralympics, Clarke will be on a mission to prove his critics wrong in the under-90kg division.
"Out of the 12 of us, 10 could take it so it's going to be a good, old-fashioned bitch fight," the South Australian said.
Whatever the outcome, Clarke knows the battles he's fought will all be worth it.
Although describing judo as a vicious sport, Clarke said it's also renowned for the bond between top competitors.
He was in Lithuania earlier this year when a highly competitive fight between him and Germany's Sebastian Junk turned to laughter.
"We're on the ground I'm trying to strangle him and we thought we heard, matte, which means stop the fight.
"He says `Was that matte called?' and I go, `Oh no, I don't think it was' and I'm still strangling him and we're both laughing at the same time.
"It's one of those rare moments in high competition where you can have a bit of fun with your players.
"Then of course, we stood up and proceeded to beat the living daylights out of each other again."
