Robert De Niro punched Sylvester Stallone 'a couple of times' while filming 'Grudge Match'.

The 'Rocky Balboa' star admits he wanted to take the boxing scene in the comedy movie further than acting, so he allowed De Niro, who has two Oscar Awards under his belt, to smash him across the face and knock him to the floor to make it feel like a real fight.

Stallone told the Confidenti@l column in the New York Daily News newspaper: 'I told him [De Niro], 'In here, your Oscars are not going to help you pal, you're in Rockyland.

'He was very feisty, he took a good shot. It was very, very hard, the training. He hit me a couple of times because, you know, you want to get that realism. But when I saw him take some falls and I took some falls I said, 'This is getting good, this is not a joke fight.' '

However, the 67-year-old actor admits jumping into the ring with De Niro, 70, was harder than he thought it would be because they couldn't pull off the same stunts they could during their younger years.

Although, he believes the film - which follows a pair of ageing boxing rivals who are coaxed out of retirement to fight one last time - suited him down to the ground because it was very 'age appropriate'.

Stallone explained: 'We weren't jumping around like we were 22, even though I wanted to; I wasn't able to.'