A growing number of broken beer bottles crunched beneath their feet as thousands of Leicester supporters continued singing past midnight on the city's High Street on Sunday.

"Champions of England," the chant went, "we know what we are."

Few around the world will not know. Singing it perhaps reminds Leicester fans that the past year is real and not some improbable sporting fantasy.

It was little surprise that Leicester Royal Infirmary reported twice the usual number of patients being admitted during the Saturday night revelry, mostly for minor injuries or alcohol-related incidents.

People were urged to avoid seeking medical attention unless it was urgent, with the hospital tweeting that it is "feeling the effect of the (Leicester) game yesterday. If you don't need to come to A&E please don't."

Sunday marked Leicester's seventh day as one of the unlikeliest champions of England since the country's leagues were established in the 19th century.

The solid silver Premier League trophy, topped by a golden crown, was presented the previous evening to the Leicester players after they overwhelmed Everton in a 3-1 win with a display that showed they are taking the final two games of the campaign seriously.

"It's unbelievable — you've seen the team spirit that we've got," said top-scorer Jamie Vardy, whose double on Saturday took his tally to 24 for the season. "It is a scandal how we all are together. We literally are like brothers.

"When training and matches are finished, we'll all go out and have food together, we're always in touch with each other. That just shows how much as a unit we all are as a team and it shows in our performances week in, week out."

But even Leicester manager Claudio Ranieri publicly accepts that this season could well be a one-off high-point for the team, which has only lost three league games in the title charge after starting out as 5,000-1 longshots and relegation candidates.

Rival managers are wondering if underdogs winning the league will become the new norm.

Arsenal is enduring a 12-year title drought despite significantly outspending Leicester, which has completed a seven-year rise from the third tier to win its first championship.

"Maybe a team that nobody expects now will come next season and surprise everyone," Arsenal manager Arsene Wenger said. "All the English clubs have the money to buy now. You've got West Ham moving into a new stadium with more potential with the finances that brings. Tottenham are creating a new stadium as well.

"So in a few years the potential in England will be much more shared than everywhere else and you can get more surprises."

One Manchester United fan turned up at Leicester on Saturday with a poster saying: "A trophy earned not bought."

Wenger, though, points out that Leicester's owners — Thai retail group King Power — are wealthy. It's just that Leicester hasn't spent heavily on players to upset the established elite like Arsenal.

"Let's not forget Leicester are not poor," Wenger said. "But they've done extremely well with less resources and their efficiency level between money spent and results are by far the best in Europe, and you have to give them credit for that."