Sean Strickland has caused a monumental upset at UFC 293 in Sydney, defeating Israel Adesanya to claim the middleweight title.
With the Australian crowd firmly in his corner, Strickland rocked the champion in the first round and proceeded to outpoint him over the next four to win a unanimous decision win, four rounds to one.
UFC president Dana White has called it the biggest upset in the company's history.
The American persisted with forward pressure, forcing the champion to evade the danger.
Strickland's defence was almost impenetrable as Adesanya struggled to find his chin.
A frustrated crowd began booing Adesanya for his evasive tactics as Strickland walked down the Nigerian-Kiwi while screaming at him to engage.
"I worked my ass off I give up so many brain cells everyday, this the first time I am lost for words", Strickland said.
Strickland picked Adesanya apart with his crisp jab and was unable to respond or mount any significant offence.
"Australia and the fans motivated me, when I heard you, guys yelling it healed me!"
Strickland scored 49-46 across the board after connecting with force in spurts and pressuring the entire way through.
White said Adesanya looked flat in the octagon tonight.
"He looked like he was in slow motion, Israel looked very stiff tonight."
Adesnaya opted not to speak to media following the fight, addressing the room briefly before handoing the microphone to coach Eugene Bareman.
"Life throws curveballs, I lost to the better man on the night, I'm gonna go chill, and be with my family."
Bareman gave full credit to Strickland and offered no excuses.
"Sean is a great fighter, I never thought he was incapable of beating Israel. Izzy had an off night, training camp was great, it was a frustrating night."
Bareman joked that he asked for a rematch next weekend.
"I've been involved in a few rematch camps, they are very difficult, you are trying to find other stones to unturn but we will find something. I am very confident we can change the outcome of this fight."