The marquee UFC 291 fight between Michel Pereira and Stephen Thompson was scratched hours before the event began in Salt Lake City, per UFC reporter Megan Olivi and ESPN's Marc Raimondi.

The UFC said the fight was scratched "due to Michel Pereira weighing in over the welterweight limit," per Raimondi.

Prior to the fight, USA Today's Nolan King reported Pereira weighed in at 174 pounds, three over the welterweight limit. This is the second such UFC incident for the Brazilian fighter, who was one pound over the welterweight limit before a 2019 bout with Tristan Connelly.

Thompson, at 170.5 pounds, came in under the limit.

The bout could have been one of the biggest of Pereira's career. He is on a five-straight active win streak, the longest among UFC welterweight fighters, and Thompson was set to be his biggest competition yet.

Pereira was not the only fighter to miss weight prior to UFC 291. Vinicius Salvador, who is set to face CJ Vergara, came in 2.5 pounds over the flyweight limit and was fined 20 percent of his fight purse, per MMA Junkie. The catchweight fight will still proceed.

That's a similar penalty to what Pereira faced last time he failed to make weight in Vancouver. He went ahead with his fight against Connelly three years ago but was forced to concede both a tough loss and a fifth of his purse.

That failed weigh-in earned Pereira a warning from welterweight Diego Sanchez prior to UFC 167 in February 2020. Pereira is a former middleweight.

"If he misses weight for this fight, there will be no fight... I will not accept this even if it's by one pound. Even if it's by .2 of a pound. I will not accept this," Sanchez told MMA Fighting in 2020. "So that if it does happen, it has been said... He will have to learn the hard way that he is a middleweight and not a welterweight."

Although Pereira made weight before his 2020 bout with Sanchez, his second miss in the division could earn him similar pushback from fellow welterweight fighters in the future.