A man who tried to rob a restaurant in Philadelphia found out the hard way that it takes a very sharp knife to make sushi.

Police said that around 3:30 p.m. Thursday, an armed 19-year-old man tried to rob the Terryin Sushi Bar at 358 Snyder Ave. in south Philadelphia but the restaurant owner stabbed the would-be robber in the back twice with a razor-sharp sushi knife.

The sushi bar had already been robbed twice before over the past three weeks.

Police believe the same man is responsible for those crimes and for robberies at a nearby grocery store and a pizzeria.

The suspect was taken to a hospital, where he was listed in stable condition and placed under police guard.