Dana White declared "the system worked" after staging UFC 249, clearing the way for professional sports to "come back safely" amid the coronavirus pandemic.
The event - originally scheduled for the middle of April - was held behind closed doors in Jacksonville, Florida, on Saturday, with all involved subject to stringent testing.
Ronaldo 'Jacare' Souza returned a positive result, along with two of his cornermen, and while asymptomatic, was subsequently removed from the card. The Brazilian had been scheduled to face Uriah Hall in a middleweight bout.
White believes the situation with Souza demonstrated just why the protocols were put in place - and promised UFC will learn from the experience and improve in the future.
"The whole world is weird; this whole event is weird. We live in a different world than we did two months ago, and the bottom line is the system worked," he said in the post-event press conference.
"The system is that you want to find people. What you don't want to do is say two days after the fight is that Jacare tested positive, you know. It worked – the system worked that we put in place.
"Without sounding like a jackass, we're really good at what we do. The way this went, we will just get better.
"We will be better by Wednesday, then better by Saturday, then after Saturday we will start to catch our stride and get this thing dialled in and figured out.
"The longer this goes, the better testing technology will get, and the faster it will get. We are going to prove by next Saturday that professional sports can come back safely."
White later added: "When we are testing all of our employees and our fighters, we will find out who has this thing [coronavirus] and will help them.
"You don't want people to test positive, we want everyone to test negative, but this week we are going to be doing 11,000 plus tests. Somebody was going to be positive – it's impossible not to be [the case]."
White also revealed that other sports associations had been in touch with him to ask about the processes involved in UFC 249, while he was also congratulated on his work by United States president Donald Trump.
"We can share what we learned here with other sports leagues, who are reaching out and asking," the UFC boss said.
"Sports leagues - and states - are asking us. A lot can be learned by what we are doing here, not just for professional sports but sending people back to work, lots of other things in life."
On Trump, who recorded a video message that was aired during the broadcast, White commented: "He wants sports back. He wants to do it in phases and he thinks sports should come back first, then figure out how to get people back to work and kids back in school."
"We came out and were first and he congratulated us on that. I thought it was nice of him."
As for the action inside the octagon, Justin Gaethje defeated Tony Ferguson to become interim lightweight champion, while Henry Cejudo announced his shock retirement after retaining the bantamweight title against Dominick Cruz.