Arriving on stage to the strains of I Want To Hold Your Hand, the two veteran musicians began pushing and shoving each other like a couple of schoolboys.
And then as Ringo delivered his opening lines Macca did his best to undermine him.
"The game is good, the graphics are very good, and we were great," said the drummer. At which point his chum mouthed: "I was great" and then pointed at his mate while shaking his head as if doubting his contribution.
Beatles Rock Band is a karaoke-style game which allows players to enter the world of the musicians, taking them to locations such as the Cavern Club in Liverpool and New York's Shea Stadium where the Fab Four played.
The Liverpool lads appear as 3-D models in various sequences, prompting Paul to joke: "Whoever thought we would end up as androids?" as his friend feigned a robotic walk.
Also joining in at the lighthearted event were Olivia Harrison, wife of the late George Harrison and John Lennon's widow Yoko Ono.