Well, what a night!

Over the past 12 hours, this weekend’s main card at UFC 279 in Las Vegas has transformed beyond all recognition with three new bouts being announced to take place at the T-Mobile Arena following a dramatic turn of events at Friday’s weigh-ins.

The turmoil began when Khamzat Chimaev unexpectedly hit the scales at 178.5lb on Friday afternoon, missing weight by a whopping 7.5lb for his welterweight main event against Nate Diaz.

That threw the contest into serious doubt with Diaz having already successfully weighed in at the 171lb limit permitted for a non-title fight earlier on during the afternoon.

BT Sport’s Ariel Helwani reported the reason behind Chimaev’s shock weigh-in fail had been attributed to an undisclosed “medical issue” but the incident incensed the Diaz camp who quickly made it clear Nate would not be fighting Chimaev as a result.

“They believe Chimaev didn't even try to make the weight and is basically cheating,” MMA journalist Cole Shelton tweeted.

In danger of the pay-per-view falling apart, the UFC frantically set about repairing the damage by recalibrating the trio of fights set to top the bill previously during talks with six fighters throughout Friday evening.

“We're going to have some fun!”
- Tony Ferguson

UFC boss Dana White took to Instagram Live late on Friday night to announce the new-look UFC 279 main card.

Diaz will now take on fellow veteran and fan favourite Tony Ferguson in a five-round welterweight main event that sees the two Ultimate Fighter winners finally get a chance to tango in what should be a cracking contest between two men at similar stages in their careers.

Responding to the late change of opponent with typically fruity language, Diaz said: “Tony’s been around a long time, we should have fought a long time ago.

“Khabib [Nurmagomedov]’s b****a** was afraid of him just like this b****a** motherf***** was afraid of me yesterday. We punched his b****a** in the back here and now he doesn’t make weight.

“You guys already know what it is. Real Gs come from California.

Ferguson added: “Grab your f****** popcorn and blue Slushees motherf****** because we’re going to have some fun!”

Chimaev, meanwhile, takes on Kevin Holland in one of five catchweight contests now set to take place at UFC 279, fighting in the co-main event over five rounds.

The pair almost came to blows at the fighter hotel earlier this week, as well as backstage during part of the skirmish that eventually led to the cancellation of the UFC 279 press conference on Thursday.

Chimaev emerged to a booing crowd at the ceremonial weigh-ins late on Friday night but had little to say about his failed weight cut, telling Joe Rogan: “They [UFC doctors] stopped that sh*t [the weight cut], I don’t know.

Ferguson’s previously scheduled opponent, Li Jingliang, will now take on Daniel Rodriguez, who had been set to face Holland, in the third rejigged bout of the evening.

The chaos of the last few hours is unlikely to have sat well with the UFC brass, but many fans, journalists and even fellow fighters have greeted the new-look line-up as an improvement on what was previously set to go down this Saturday night.

“I don’t want to reward all the s*** that went down…but these fights just got way better!” UFC featherweight champion Alexander Volkanovski wrote on Twitter.

MMA journalist Shaheen Al-Shatti added: “If the current plan actually happens? First time I've ever seen a botched weigh-in day make a UFC card infinitely better than its original form. What a sport.”

It was not one of the finer afternoons in UFC history with two more fighters also missing the mark at the weigh-ins.

Featherweight Hakeem Dawodu and heavyweight Chris Barnett – who became only the second man to miss the 265lb limit in promotional history – also failed in their efforts on the scales, although both will remain on the card with financial penalties incurred.

Click here for all the updated information about UFC 279 and all the ways to watch it go down exclusively live on BT Sport tonight.