Mojo Muhtadi put the break in dancing over the weekend … suffering a GNARLY shoulder injury while partying with Ryan Cabrera in Las Vegas!

The ex-WWE Superstar turned TMZ Sports TV show co-host was at Ghost Bar at the Palms Saturday night for Cabrera’s performance … when a dance battle busted out.

Never one to turn away from an opportunity to dance, Muhtadi *attempted* a diving shoulder roll … that went very wrong.

But, injury or not, Muhtadi, who was in Vegas hosting several events around WrestleMania weekend, wasn’t going to cut the night short and head to the hospital.

Instead … Mojo continued to party, and then returned to his hotel room for the night, hoping a solid few hours of sleep would be all the medicine he needed.

Sunday morning came and the shoulder was still busted, so MM headed to see a local doc … where they took this doozy of an X-Ray.

The diagnosis? A grade III AC (acromioclavicular) joint (total) separation.

Thankfully, he doesn’t need surgery … docs say after a couple of weeks in a sling, he’ll be nearly as good as new. In fact, Mojo attended a full day of events on Sunday … which even impressed his pals, including a former wrestler, who is no stranger to crazy injuries.

“Some things never change—Dean has always been known for bringing the hype. But seeing him return on Day 2 after a shoulder injury and finish the contest gave a whole new meaning to what being HYPE really is,” Mandy Sacs told us.

As for the man performing at the time of the busted shoulder … Cabrera said it was an unforgettable night.

“Watching Mojo split his shorts during the dance battle at my set was the highlight of my DJ career!!! It is a true testament to his dedication to winning, the man even dislocated his shoulder.  I’ll never unsee what I saw that glorious evening!” Ryan Cabrera said.