Conor McGregor said on Sunday his right knee was fine before he injured it on the first kick of his mixed martial arts showdown with Max Holloway to end a five-year layoff.
And the Irish star who lost in 69 seconds at UFC 329 in Las Vegas vowed to make another comeback once he recovers from his latest setback.
McGregor injured himself when he planted his right leg to make a leaping roundhouse kick at the start of the bout, falling to the mat for the first of three times before the fight was stopped.
"I was so sharp and so ready for this fight, I cannot believe what has happened," McGregor posted on X on Sunday after the bout.
"The talk of me being off while walking into the fight is nonsense. I was calm, ready, and confident. I am in shock what has taken place."
McGregor, who had not fought since suffering a broken left leg in a 2021 defeat, promised his famed career was not yet over.
"I will overcome this," he wrote. "I will not be deterred. I will return."
'CAME OUT OF NOWHERE'
McGregor described his injury as "my head gasket is gone. Destroyed," in a cryptic reference taken to mean torn knee ligaments.
"I had no injury/injuries going into the fight," McGregor posted.
"I was throwing kicks, planted and jumping, all throughout camp as well as backstage before the fight. This came out of nowhere."
McGregor described his situation as, "I am beyond dark here. I can only describe it as hell."
Triumphant Holloway, who joked of making McGregor "weak in the knees," said he wants to fight McGregor again whenever possible. He lost their first meeting in 2013.
"Thank you Conor for fight. Took a lot to make that walk after these past few years," Holloway posted on X. "Sending prayers for a speedy recovery."