Like much of Dirty Boxing's debut show, which was held as a private event at an undisclosed location in Miami, Romero’s involvement was kept under wraps until he unexpectedly showed up to Friday's weigh-in for a heavyweight showdown against Power Slap veteran Duane Crespo.

The promotion’s inaugural event featured familiar names like former PFL prospect Solomon Renfro and former UFC light heavyweight Fabio Cherant. In an unprecedented move, Perry and Dirty Boxing won’t stream the fights live, and will instead opt to release the fights the day after on its platforms.

Jon Jones was shocked by Yoel Romero's knockout at the 'Dirty Boxing' event, caught on camera in a viral reaction.

Yoel Romero is fighting this weekend. Yes, you read right. The former multiple-time UFC title challenger returns to action this Saturday in Miami, Fla., at Dirty Boxing Championship – a striking promotion owned by Mike Perry.

Check out the best photos from Yoel Romero's first-round knockout over Duane Crespo at Dirty Boxing Championship in Miami. (Photos courtesy of Dirty Boxing Championship)

Yoel Romero still has it at 47 years of age. The former UFC title challenger helped ring in the debut event for Dirty Boxing Championship (DBC), which is a promotion created by bareknuckle brawler and former UFC fighter Mike Perry.

UFC star Yoel Romero scored a vicious first-round knockout at the inaugural Dirty Boxing Championship event in Miami. Romero’s return to action on Saturday night came as a shock to everyone as the promotion opted to provide little detail on its first-ever event until it was time

Check out UFC and Bellator veteran Yoel Romero as he demolishes Dana White’s Power Slap fighter Duane Crespo at Saturday’s Dirty Boxing Championship event.