Conor McGregor has fired the first verbal volleys at Floyd Mayweather.
The UFC Champion steps into the squared circle to box the undefeated professional boxer on August 26th.
McGregor made light of Mayweather's tax troubles and vowed to knock him out in 4 rounds:
"These boxing press conferences are a completely different setup than what we are used to, but 20,000 people, it is mind-blowing.
"I am absolutely honoured to be here before you to give you this great spectacle," he said. "And somebody's 0 has got to go!
"There's no other way about it. His little legs, his little core, his little head. I'm going to knock him out inside four rounds, mark my words.
"The movement, the power, the ferociousness - he's not experienced this. He's fought people who have shied away from him. I don't fear this limited set of fighting.
"This is a limited set of rules that makes this half a fight, a quarter of a fight. If this was a true fight, it wouldn't even take one round.
"What can I say, I'm a young, confident, happy man who has worked extremely hard for this."