MIAMI-DADE COUNTY, Fla. – A man in Northeast Miami-Dade heard a commotion coming from outside his front door.

When he opened the door after hearing his neighbor calling for help, the man was ambushed by the woman and another man.

Those crooks weren’t counting on the man at the door fighting back.

Barry Sands isn’t someone you want to mess with, and police said one man clearly found out the hard way.

"(I heard) knocking like crazy," said Sands. "I get up, I don’t even have shoes on."

Sands was asleep Saturday night when investigators said his neighbor knocked on his door asking for help after getting into an argument with her boyfriend.

When he opened the door, investigators say 35-year-old Mark Katsnelson forced himself inside, throwing punches at Sands.

Sands, a 65-year-old self-trained boxer, responded.

"He was out, I mean he was out," Sands said, adding that he punched the intruder "as many as I could.”

Mugshot for Mark Katsnelson. (WPLG)

Katsnelson ended up at Ryder Trauma Center where he was treated for several injuries before being booked in jail with a slew of charges, including assault.

Katsnelson had a warrant out for his arrest on multiple counts of drug possession. He remains in jail without bond.