Karl Rogers and Adrian Sanchez were arrested in San Antonio, Texas, for attempted burglary, reports KSAT-TV.
Police said that Rogers broke into the Northwest Side martial arts gym, but was met by MMA fighters who were still inside training.
MMA fighter Caleb Murphee told KSAT-TV: "We're just kind of sitting down, drinking water, talking about what's going on, and we start to hear pounding on this door."
Murphee and another MMA fighter grabbed some weights, which they planned to throw at Rogers, but he fled before the weights went flying.
Police officers arrived at the gym and found Sanchez, the getaway driver, hiding in a parking lot.
Police caught Rogers running around a corner. Rogers was carrying a hatchet, but the cops talked him into dropping it.
Both Sanchez and Rogers were taken into custody.
Murphee added: "If he would have tried to rough me up or something, yeah, I definitely would have defended myself. I feel confident I would have come out on top."