Timothy Spall says he is "finally a leading man" after being crowned best actor at the Cannes Film Festival for Mr Turner, a portrait of England's greatest landscape artist, JMW Turner.
"Actors are divided into two camps,'` he told BBC News. "Those who get the good-looking, wish-fulfilment parts and then the supporting actors like me who get the real-life roles. I've been lucky enough to have many of them, but there are not many prizes to be had in a supporting position.
"Finally though, with Mr Turner, it feels like someone has made me into a leading actor - albeit an ugly one."
The 57-year-old star, known among younger cinema audiences for his part as Peter Pettigrew aka Wormtail in the Harry Potter films, spent five years with director Mike Leigh researching the role of the artist, a man Spall describes as an "eccentric genius".
Mr Turner received rave reviews after its world premiere at this year's Cannes Film Festival, and had been hotly tipped for reward but, according to Spall, when the call came, "it was still a shock".
"I was on my barge in Holland, up to my elbows in grease, a spoon and toilet paper in my hand, when the phone rang," he said. "They wouldn't tell me I'd won, they just said I had to come back to the South of France for the award ceremony. So I hopped in the shower and now a few hours later, here I am close to tears with pride again. I've been blubbing all evening."
Born in Battersea, south London, Spall trained at the National Youth Theatre and Rada before finding fame on TV as the lovable, awkward electrician Barry in Auf Wiedersehen, Pet.
He first worked with Leigh on the film Life is Sweet as the appalling chef Aubrey, whose signature dishes included saveloy on a bed of lychees and liver in lager.
Since then, Spall has been nominated for five Baftas and has been a steady presence both in British film and TV and Hollywood fare, starring opposite the likes of of Johnny Depp, Tom Cruise and Jim Carrey.
During an emotional acceptance speech in Cannes, the actor described himself as "always the bridesmaid, and now at last a bride" but also paid tribute to Mike Leigh, the 71-year-old director of Mr Turner, with whom Spall said he "shared the prize."
The actor also starred in Leigh's Palme D'Or winning movie, 1996's Secrets and Lies. Spall was unable to attend the ceremony at Cannes that year as he was suffering from leukaemia.
"Mike and I have worked together on numerous occasions and he's always offered me the best parts of my career," Spall said. "I was devastated I couldn't be here in 1996 for Secrets and Lies but I was hooked up to a chemotherapy machine.
"And this is what makes it so great for my wife and family, after thinking they might lose me that, 18 years later, I would be at the Cannes Film Festival again, winning for Mr Turner. It's a rare moment.
"So this is partly why this win is as much about Mike Leigh as it's about me. We spent so long researching and filming, and what we've produced is the world of a real English hero - he was no Byron or Keats, Turner was just a funny little fat man who happened to have genius at the touch of his fingers on a paintbrush.
"I'm a funny little fat man too, but it's the performance on screen that the critics have responded to. So it's not really about me, but I am so touched and so humbled by this reward. I'm a happy man."