Sylvester Stallone and Robert De Niro traded real punches in their new boxing movie “Grudge Match.”

In the film, the actors play aging boxers who come out of retirement for a final showdown. Stallone, 67, admits that 70-year-old De Niro packed real punches and took genuine hits while they were in the ring together.

Stallone said, “Once [De Niro] commits, he goes all the way. He took some serious hits and falls. He won’t admit it, but he did… He was on the east coast and I’m training on the west coast. It’s the equivalent of having a ballet recital and you don’t meet your partner till the curtain goes up and you hope it all works out and it did.”

Director Peter Segal added, “I wanted the reality and those guys, unfortunately, weren’t able to do perfect movie punches every time. They connected quite a bit. You can see their backs and shoulders got scarred up by the ropes.”

It’s been a while, but both stars previously took real punches while playing boxers in films: De Niro in his Oscar-winning performance as Jake La Motta in “Raging Bull” and Stallone in six “Rocky” films.

J-Connection: Sylvester Stallone’s mother is of Russian Jewish and French descent.