His break came in the ITV comedy-drama Fat Friends, where he met Ruth Jones, with whom he would go on to created the BBC Three hit Gavin and Stacey. However, before that he would appear in Hollyoaks as Wayne and in Alan Bennett's play The History Boys, which opened in 2004. He played Timms in the London, Broadway, Sydney, Wellington and Hong Kong productions, and in the radio and film adaptations.
Gavin & Stacey, which started in 2007, made his name. He won best male newcomer nomination at that year's British Comedy Awards, and the show won best new TV comedy. On the show, he struck up a friendship with co-star Mat Horne. They have since hosted Big Brother's Big Mouth together, as well as various awards ceremonies, and a critically slammed sketch show
But then he reinvented himself as the host of Sky's sports panel show League Of Their Own, and co-creating the BBC Two comedy-thriller The Wrong Mans.