The UFC world has been left stunned after the Vegas 107 main event was cancelled at the last possible moment after Maycee Barber suffered a seizure.

Barber was supposed to be returning after a 14-month layoff due to several health issues to face rising contender Erin Blanchfield.

However, she never made it to the UFC Octagon after suffering a seizure as she started to make the walk.

Barber missed weight ahead of the card as concerns about her health lingered but no one would have expected what happened on Sunday.

After the UFC broadcast played the pre-main event video package, no fighter emerged much to the confusion of the commentators.

After half a minute of silence, Brendan Fitzgerald informed fans Barber was “not prepared to walk.”

“I’m still getting details but all I know is that she is not walking to the Octagon right now,” Fitzgerald said.

“This is truly unprecedented and for me, for a main event prepared to make the introductions and she’s not there to walk right now.”

The broadcast team quickly cut to an ad break before returning to confirm the main event had been cancelled due to a “health event.”

That health event was later confirmed to be a seizure, as fighters quickly sent their well-wishes to the 27-year-old.

“Seizures! Wow, that sounds quite serious. I really hope she’s able to recover and return to fighting. Sending prayers her way,” shared Australian UFC fighter Casey O’Neill on X.

“Prayers up to Maycee Barber,” one fan added.

While another wrote: “All the best Maycee Barber. My thoughts are with you.”