But he hadn't banked on Superman catching him, then handing him over to the police!
Luke Junior, 24, was dressed up as the superhero for a charity event nearby when he saw the man escaping from Heron Foods in Sheffield with the pinched pork and knew he couldn't let him get away with it.
Luke said: "He came running out of the store as I was having my photo taken with some kids. The manager shouted, 'Stop him!' so I ran after him and grabbed him tight. The last thing you want to do is run straight into Superman.
"Everyone was cheering. Then the DJ put the Superman music on. I went back to the kids and, as Superman would, told them to stay on the right side of the law."
But this isn't the first time Luke has come to the rescue - the shopping centre security guard also helped two people out of a car crash and was nicknamed Superman by his friends then.
"When I was younger I wanted to be some kind of Superman. Now it's like I already am," Luke added.
A 38-year-old man will be sentenced this month after admitting theft.