Carlos Ulberg has admitted that he lost his UFC belt just hours after winning it on Saturday.

In the main event of UFC 327, Ulberg fought former champion Jiri Prochazka for the vacant light-heavyweight title, and few could have foreseen the way the bout panned out.

Ulberg, 35, sustained a knee issue early in round one, but he fought through that injury to knock out Prochazka in the same frame.

Prochazka later claimed with regret that he had shown “mercy”, but in an interview with Yahoo Sports, Ulberg dismissed that claim and suggested that the Czech will not get an instant rematch.

But Ulberg’s tone softened in an interview with Fox Sports Australia, when the New Zealander discussed what happened to his title belt on Saturday.

“I’ve lost the belt, bro,” Ulberg said. “I don’t know exactly where it is.

“Initially after winning, the plan was to not have a drink, but you know how these things go, right? First, someone gives you a champagne to celebrate. Then one thing leads to another and you’re doing shots, so it’s: ‘Okay, I’ll have another, and another, and another…’

“We’ve got a big group of boys over here in Miami and, when the fight was done, we all went out to the afterparty at a night club. Then after that, it was back to one of the boys’ apartments and we all hung out there.

“I didn’t want to be carrying the belt around, so I think it’s still there at the apartment somewhere. One of the boys probably has it in bed with him.”

There has been genuine concern that Ulberg could lose the title for good, though; with his knee injury looking serious, some fans fear that “Black Jag” might need to vacate the gold soon after having won it.

“My knee is really swollen, so I’ll stay in the US for scans. And then if I need to go under the knife, I will,” Ulberg said.

“I think I’ll fly to Las Vegas in the next few days and see the doctors there. Then I can do physio at the UFC Performance Institute and get looked after by the guys there. That’s the plan: get the knee sorted in Las Vegas and hang around for a few weeks.

“I’ve been hobbling around everywhere, so my knee isn’t really wanting to forgive me right now. It’s all been a crazy, crazy whirlwind, and I’m just going with it.

“It’s been a bit like when I was kickboxing, and broke my hand during King of the Ring. It was in the second fight on a night where I fought three times. Then after fighting, I’d actually booked a holiday that weekend, so still went away. It was only after getting back that I went and saw a doctor who said: ‘You need surgery.’ I already knew and said: ‘Okay, let’s get it done.’ And I think that’s what we’re facing now.”