LEICESTER(AFP) - Leicester City's heroes celebrated with lunch at an Italian restaurant on Tuesday (May 3) after achieving one of the biggest upsets in sporting history by winning the English Premier League.

Thousands danced in the city's streets waving blue and white flags, while millions around the world watched in wonder as the one-time 5,000-1 underdogs sealed the title on Monday night.

The unthinkable happened thanks to second-placed Tottenham Hotspur being held to a 2-2 draw at outgoing champions Chelsea.

After players and fans celebrated late into the night, the team, including Italian manager Claudio Ranieri and top scorer Jamie Vardy, dined out at the city's San Carlo restaurant on Tuesday to celebrate becoming champions for the first time.

As hundreds of fans crowded the street outside, they tucked into lobster, fish and meat - but the players skipped the champagne for now, according to the restaurant's manager.

"I don't know the secret. The players, the heart, the soul and how they play," said Ranieri in an interview with Sky Sports, explaining his extraordinary success.

"It was an amazing achievement. We wanted to do something special, but no-one could have believed we would do this."

Last season, Thai-owned Leicester narrowly escaped relegation and were rated as no-hopers this time around.

But in the event, the east Midlands club outshone some of world football's most glamorous teams.

Their record of 22 wins in 36 games with just three defeats was enough to make them champions ahead of Arsenal, Manchester City, Manchester United, Liverpool and Chelsea.

The players can look forward to another party when they receive the Premier League trophy at their 32,000-seater King Power Stadium following Saturday's home game with Everton.

"I am going to try to hold back the tears," said captain Wes Morgan on the prospect of lifting the trophy.

"It hasn't sunk in yet. It was a long night celebrating. After the initial euphoria, a lot of people couldn't believe what had happened. It's an achievement that might not be achieved again."

Along with other players, Morgan was pictured at a euphoric celebration on Monday night at Vardy's home in the nearby town of Melton Mowbray after they gathered to watch the Tottenham-Chelsea game.

The Foxes are England's first first-time champions since Brian Clough's Nottingham Forest in 1978.

They have won admirers across the globe through their surge to the summit of the world's most-watched football league, which attracts billions of pounds in television rights deals.

Leicester's success, which ensures they will play in the lucrative Champions League next season, could be worth around £155 million (S$305 million) in revenue to the modest club, up from £104.4 million for last year.

"This is going to really elevate them, at least for one season, to the next level commercially," Mr Tim Bridge, from financial consultants Deloitte's Sports Business Group, told AFP.

"The challenge for Leicester is, how do we keep hold of those players and how do we plan for the future in a sustainable manner?"

Britain's newspapers turned blue in homage to the team's win, while The Economist magazine asserted: "There has never been a more improbable victory in any sport."

Vardy, whose meteoric rise from the lowest ranks of English football to scoring 22 goals this season has made him an unlikely folk hero, announced on Tuesday that he will release an autobiography, My Story, in October.

British Prime Minister David Cameron sent his congratulations to Leicester, calling it an "extraordinary, thoroughly deserved" title.

Mr Gianni Infantino, president of football's world governing body Fifa, said: "It's one of these beautiful football stories that only football can write. This is the magic of football."

However, Real Madrid coach and French football great Zinedine Zidane said Leicester's title was all down to talent and hard work.

"Miracles don't exist in football. They have had a phenomenal season. Ranieri has done a phenomenal job," he said.

After a night of car horns honking in celebration, the title was the sole topic of conversation in Leicester on Tuesday, with many people still wearing their scarves in the streets.

In the Gourmet Cafe, waitress Stacie, 25, said takings were down, probably "because people didn't go to work".

"They are not hungover yet," she explained. "A lot of people are still drunk."