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)

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 for the fighters to weigh in.

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 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. Romero’s return didn’t fly under the radar; the promotion literally announced the fight on Friday evening, hours before the event.

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.