The Greatest Underdog Stories in Football

May and June have a way of delivering the moments that are hard to forget.

The Premier League title race wraps up on 24 May, when things that haven’t yet been are decided.

The Champions League final in Budapest on 30 May brings the continent's best clubs to one stage, one game. Winner takes all. The Europa League final takes place a week earlier on 20 May.

And then, just as the dust settles on club football, the 2026 FIFA World Cup kicks off on 11 June, with 48 nations, three host countries and the most expansive tournament in the competition's history.

If you want to be involved in any of it, we’ve got the markets. Outrights, match betting, group winners, top scorer. Whether the action is in Budapest, a World Cup stadium in the United States or the final day of the Premier League, you can back your call and watch it unfold.

First, though, a reminder of why the biggest occasions in football are worth paying attention to. Because the history of the game is full of teams who weren't supposed to be there, weren't supposed to win and did it anyway. These are some of the best of them.

Leicester City — Premier League, 2015/16

Start here, because nothing in football history quite compares.

Leicester City began the 2015/16 Premier League season at odds of 5,000/1 to win the title. For context, bookmakers were offering shorter odds on Elvis Presley being found alive. They were a team that had spent most of the previous decade in the Championship, managed by Claudio Ranieri, a well-liked journeyman with a reputation for steady, considered management.

What followed over the next nine months was the most improbable title win the English game has ever seen. Jamie Vardy broke the record for scoring in consecutive Premier League games. Riyad Mahrez was named Player of the Year. N'Golo Kanté covered every blade of grass on every pitch he played on. And Ranieri guided a squad assembled for a fraction of their rivals' budgets to the championship by 10 points.

The city of Leicester stopped. The footballing world stared. And for anyone who had backed them at the start of the season – the few of them – it remains the greatest return in the history of outright betting.

Nottingham Forest — European Cup, 1979 & 1980

Brian Clough was not a man who did things quietly or conventionally. His Nottingham Forest side, promoted from the Second Division in 1977, won the First Division title in their first season back in the top flight. Remarkable enough. What came next was something else entirely.

Forest won the European Cup in 1979, beating Malmö in the final with a goal from Trevor Francis, the first £1 million footballer in British history, signed by Clough with characteristic flair. A year later, they did it again, defeating Hamburg in the final in Madrid. Back-to-back European Cups. A club from the East Midlands, with a manager who trusted his instincts over everything else, had become the best team on the continent two years running.

It's a story with a present-day echo worth noting. Nottingham Forest are back in European football this season, competing in the Europa League for the first time in the club's history. The wheel turns.

Denmark — Euro 1992

Denmark did not qualify for Euro 1992. That detail is worth sitting with for a moment.

Yugoslavia had been withdrawn from the tournament due to the civil war, and Denmark were called up as replacements with less than two weeks to go. Several of their players were on holiday. The squad assembled and travelled to Sweden with modest expectations and very little preparation time.

They drew their opening group game, lost their second and scraped through on goal difference. Then something shifted. They beat the Netherlands on penalties in the semi-final — the Dutch, with a squad that included Gullit, Rijkaard and Van Basten at the peak of their powers. And in the final, they faced Germany, the reigning champions.

Denmark won 2-0.

Peter Schmeichel was immovable in goal. A young Brian Laudrup was electric. A squad that hadn't even known they were going to a tournament a fortnight earlier came home as European champions. It remains one of the most extraordinary results in the history of international football.

Greece — Euro 2004

Greece were ranked 80th in the world when Euro 2004 began in Portugal. Otto Rehhagel's side were organised, disciplined and given absolutely no chance by the vast majority of pundits and bookmakers.

They beat the hosts Portugal in the opening game. They beat France – the Euro 2000 champions – in the quarter-finals. And then, in the final in Lisbon, they faced Portugal again. Angelos Charisteas headed home the only goal. Greece, 80th in the world, were European champions.

The outright odds available on Greece before the tournament were significant, to put it mildly. As a story that speaks directly to the value of backing an outsider in a major international tournament, it has never been bettered. And with the 2026 World Cup just weeks away – 48 teams, more routes to an upset than any previous edition – it's a reminder that the biggest shocks in football tend to arrive when nobody sees them coming.

Cameroon — 1990 World Cup

Cameroon's opening fixture at Italia 90 was against Argentina, the reigning world champions. They won 1-0. Benjamin Massing was sent off in the process — a challenge on Claudio Caniggia that is still being talked about — but the result stood and the tournament's defining story had begun.

Roger Milla was 38 years old, nominally retired, and had reportedly been persuaded back into the squad by the Cameroonian president himself. He came off the bench in the knockout rounds, scored four goals and celebrated each one with a shimmy around the corner flag that became one of football's most enduring images.

Cameroon beat Colombia. They beat Romania. They went 2-1 up against England in the quarter-final before eventually losing 3-2 after extra time, Gary Lineker converting two penalties to save England's tournament. They were 25 minutes from the semi-finals.

It was a run that changed how the world thought about African football, and it remains one of the great World Cup stories. With the 2026 edition expanding to 48 teams and giving more nations from more confederations a place at the table, the conditions for the next great Cameroon story are arguably better than they have ever been.

Iceland — Euro 2016

Iceland's population in 2016 was approximately 335,000. Just slightly below the size of Coventry’s population. They had never qualified for a major tournament before Euro 2016 and arrived in France with the sole ambition, as far as most observers were concerned, of not being completely overrun.

Their goalkeeper, Hannes Halldórsson, had directed music videos before turning professional. Their captain, Aron Gunnarsson, played his club football for Cardiff City. Their head coach, Lars Lagerbäck, was in his 60s and had seen everything the game had to offer.

None of it mattered. Iceland beat Austria, drew with Hungary and Portugal and then met England in the round of 16. Raheem Sterling, Wayne Rooney and Harry Kane were in that England squad. Iceland went ahead through Kolbeinn Sigþórsson’s goal in the 18^th minute, withstood everything England threw at them and won 2-1.

A Viking clap echoed around the Allianz Riviera in Nice as one of the great upsets of the modern era was completed. They lost to France in the quarter-finals, but by then the point had been made emphatically.

For a UK readership, Iceland's run carries a particular charge. And as a reminder that tournament football has a habit of producing results that nobody predicted, it fits neatly into a summer when 48 nations will line up with the same belief - however improbable - that they can be the ones to surprise everyone.

Back your call at MONOPOLY Casino & Sports

The history of football is full of moments that nobody saw coming. And an upside of football outright markets is that they let you back a feeling before the tournament begins. That’s before the upsets happen, before the odds can shorten, before others catch on.

We have betting markets across the Premier League run-in, the Champions League final, the Europa League final and the 2026 World Cup. Group winners, tournament outrights, match betting and more. All are available to follow and engage with as the biggest weeks in the football calendar unfold.

Discover more at the MONOPOLY Casino & Sports blog, where football's greatest upsets sit alongside betting guides, casino tips and everything you need ahead of a summer of sport.