01/08/2011 06:00 BST | Updated 30/09/2011 06:12 BST

Craig Roberts Reflects On How Submarine Success Has Meant Working With Robert De Niro, Sigourney Weaver

“I couldn’t act when I started, and I basically learned on the job.”

Craig Roberts is being impressively understated about his work in Submarine, one of the breakout hits of 2010, depicting a young Welsh teenager, Oliver, with his twin obsessions: to lose his virginity by his next birthday (16th), and to extinguish the ex-flame who has re-entered his mother’s life and threatened his family unit.

Set in a sleepy seaside town, this quietly hilarious coming-of-age tale – a sort of Welsh Gregory’s Girl – puts Roberts as Oliver at the emotional heart of the film, and sharing the screen with the object of his affections Jordana (played with equal aplomb by Yasmin Paige) as well as the far more established talents of Sally Hawkins (An Education, Made in Dagenham) and Noah Taylor (Shine, Vanilla Sky, Lara Croft Tomb Raider).

“I didn’t feel exposed,” explains Roberts, in London for the day from Wales where he still lives. “I felt responsible, but in very, very safe hands with the other actors and the director Richard (Richard Ayoade, better known as Saboo in The Mighty Boosh, which he also helped write) Every single day was genuinely a learning experience, and the shoot passed by in a blur.”

So when did he first realise that the film, exec-produced by Ben Stiller, and with it his burgeoning career, were going to enjoy such fanfare?

“The film was being shown at Toronto Film Festival last year, with all these execs sitting behind me, and I was petrified. It finished, and there was silence. And then I felt a hand patting me on the back. It was all most strange.”

Since then, Submarine has met with high critical acclaim, been released in the States, and life for Roberts, whose previous CV included staple TV fare such as Tracy Beaker, Young Dracula and Casualty extra duties, life now consists of reading scripts and fielding calls from Hollywood agents.

Projects in the pipeline include Red Lights, where Roberts will share screen-time with Robert De Niro, Cillian Murphy and Sigourney Weaver - so should we be concerned that such success, shining so soon and bright for this young man, may lead him down a wayward Lohan-esque path?

“Fear not,” advises this wise and well-mannered Welsh sprite, now a worldly 20. “My friends back in Swansea would soon put my head in a bin if I started getting ideas above my station. They’re not having any of it.”

Not to mention his own, real-life flush of first romance, with fellow actor Lucinda Dusack.

“Since making the film, I’ve experienced love for the first time myself, so it’s pretty strange going through it for real. I’m hoping she can watch Submarine and separate me from Olivier... because obviously I’m slightly less sophisticated.”

SUBMARINE is available on DVD from today.