The play's always been the thing for actor Tom Jordan Murphy, who suddenly finds himself starring in not one but two Irish films. Michael Dwyer met the busy actor in between curtain calls

Last Monday night, at the end of Conor McPherson's play Shining City, Tom Jordan Murphy joined his three co-stars for the curtain call on stage at the Gate Theatre. With minutes to spare, he did a quick costume change, shedding the track suit he wears in the play, and dashed over to the Savoy cinema for another curtain call, after the world première of Paddy Breathnach's exuberant road movie, Man About Dog, in which Murphy gets to demonstrate his flair for comedy.

One of Ireland's most adventurous and versatile young actors, Murphy has been securing meaty theatre roles for years, even winning a Tony award on Broadway at the age of 22, but substantial cinema parts evaded him until two juicy roles turned up in quick succession, in Man About Dog and Adam & Paul.

"It's the way my career has been going, in highs and lows," Murphy says philosophically, sitting in the Garden of Remembrance during a break from rehearsals at the nearby Gate. "Next year I could be doing a lunchtime in a café. Who knows?

"There are a few other movie offers out there, but I've been with this play for a long time now. It's one of the best plays I've ever been in, and it proves that Conor McPherson is as brilliant a director as he is a writer. He understands actors in a way that a lot of directors wouldn't. It's a really haunting, chilling play, but it's very difficult to discuss without giving too much away about what happens."

He explains the confusion as to why he is sometimes credited as Tom Jordan Murphy, and other times simply as Tom Murphy. "When I started acting in London, Equity pointed out that there's another Tom Murphy, who's been in the business for years. He lives up in Durham or somewhere, but he has first call on the name and he refused to stick in an initial. So I decided to add Jordan, my grandmother's maiden name."

Murphy, now 28, was born in Zimbabwe, where his father, a builder from Longford, met his mother, a nurse from Cork. The family moved back to Ireland when Murphy was very young and he grew up in Dublin, where he has been acting since childhood. "It wasn't something that I had to decide about doing," he says. It was just something that I always did."

He made his professional début as the Artful Dodger in Noel Pearson's production of Oliver! When he was nine, he played the young Christy Brown in Peter Sheridan's adaptation of Down All the Days, which Jim Sheridan directed. "It was a brilliant, brutal adaptation, which a lot of people found shocking at the time," says Murphy, who went on to major in drama at Trinity, where he became even more immersed in acting at Players.

Seven years ago, being cast by Garry Hynes in Martin McDonagh's The Beauty Queen of Leenane took Murphy on what he describes as "a whole journey we could never have imagined". It started in Galway, "and then we went on this mad tour all over Ireland, and then to the West End and on to Broadway. It wasn't planned like that. Even when we were invited to New York, we were only planning to do it for two months off-Broadway. Then it took off and bang, we were on Broadway for a year and three months. It was so unexpected that it was pure magic.

"And when you're a success in New York, they lay it all on for you. They love to celebrate success and they give you the world. We were the toast of the town - and then came the Tonys."

The production received six Tony nominations and won four, including best featured actor for Murphy. "I was thrilled to get the nomination," he says, "and I couldn't believe it when I won the thing. One actor, Sam Tramell, was supposed to be a shoo-in to win, so I just went along for the do. Armani gave me a suit and Gucci gave me shoes. When my name was read out, it felt like time stopped. I had to be pushed out of my seat to go up and accept it. It was like an out-of-body experience."

An American agent suggested he should move to Los Angeles, but Murphy returned to London and starred in two controversial productions. In the first, Handbag, "I played this down-and-out guy - I seem to have cornered the market for playing afflicted people". This was followed by Blasted, which Murphy describes as "like getting your guts wrenched out. I played this soldier who wants to tell his story. He meets this journalist, but he becomes so pissed off with him that he ends up fucking him. It's a very intense play, very graphic, and when we did it at the Royal Court there were people walking out loudly every night. But I've no problem with material like that - I've done so much of it by now."

Murphy clearly loves all the contrasts his work offers him and he welcomed the opportunity to star in a comedy when Paddy Breathnach cast him with Allen Leech and Ciaran Nolan as the three young Belfast chancers at the centre of a greyhound racing scam in Man About Dog.

"I'm choosy about what I do, and I'm lucky that I can be," Murphy says. "I thought the script was a good laugh and my character is really funny. Paddy's such a magician at his craft. He worked wonders with very limited resources. Allen and Ciaran and I got on really well from the start, and that camaraderie was important for a road movie in which we're together all the time. Paddy was well into letting the three of us loosen up on the shoot and to release all that energy we were building up on it."

Murphy says he had such a good time filming Man About Dog that it was "a real downer to go into the grim world of Adam & Paul", Lenny Abrahamson's drama starring Mark O'Halloran, who wrote the screenplay, and Murphy, as hapless Dublin junkies desperately seeking a fix.

"I'd known Mark for so long, and while he was writing it, he was always running ideas by me. I really had to dig deep to get into that guy and it does affect you when you're playing someone like that for five weeks. It was freezing when we made it last winter. I was exhausted at the end of the shoot. Even the smell off that tracksuit I wore was disgusting by the end - but I wouldn't let them wash it."

Man About Dog opens today and is reviewed on page 8. Shining City continues at the Gate Theatre, Dublin