Jimmy Fallon and Paul Rudd brought out their best rock star moves as they engaged in a hysterical Lip Sync Battle on the 'Tonight Show.'

Both men picked two songs to sing, but did not tell the other what the song was until the start of their performance. Fallon and Rudd definitely brought their 'A Game,' as they danced, moved and 'sang' their hearts out.

There was an interesting turn of events at the end when the winner was decided - watch the video below to find out who the victor of the lip sync battle was!