In the world of sports, few things are more thrilling than an underdog defying the odds and pulling off the impossible. These moments stay etched in memory—not just for their shock value, but for the raw passion, grit, and heart they represent. From obscure athletes toppling champions to unfancied teams conquering the biggest stages, these are the top 10 greatest underdog moments in sports history.

1. Leicester City Wins the Premier League (2015–16)

At 5000-to-1 odds, Leicester City’s miraculous Premier League title win remains one of the most staggering achievements in football history. A team that barely avoided relegation the previous season stunned the world by outperforming giants like Manchester City, Chelsea, and Arsenal.

2. Buster Douglas Knocks Out Mike Tyson (1990)

Mike Tyson was the undefeated heavyweight champion, widely regarded as unbeatable. Enter James “Buster” Douglas—a 42-to-1 underdog. In Tokyo, Douglas defied every oddsmaker by knocking Tyson out in the 10th round, shocking the boxing world and proving that heart can rival brute strength.

3. Greece Wins UEFA Euro 2004

No one gave Greece a chance. Yet, through disciplined defence and tactical brilliance under coach Otto Rehhagel, they toppled footballing giants like France and Portugal to claim the European Championship.

4. The Miracle on Ice (1980)

During the height of the Cold War, a scrappy U.S. college ice hockey team faced the Soviet Union’s seasoned professionals at the Winter Olympics. Against all odds, the Americans secured a 4-3 victory in one of the most iconic moments in Olympic history. The U.S. went on to win the gold medal, turning amateurs into national heroes.

5. Rulon Gardner Beats Alexander Karelin (2000 Olympics)

Russian wrestler Alexander Karelin was undefeated for 13 years and hadn’t given up a single point in six years. But at the Sydney Olympics, American outsider Rulon Gardner shocked the world by winning gold in Greco-Roman wrestling, handing Karelin his only career loss.

6. Japan Defeats South Africa – Rugby World Cup (2015)

Known as the “Brighton Miracle,” Japan’s rugby team pulled off an unprecedented win over two-time World Champions South Africa. Ranked far lower and given little chance, the Brave Blossoms clinched a 34-32 victory with a last-minute try that sent the rugby world into disbelief.

7. Emma Raducanu Wins the US Open (2021)

An 18-year-old qualifier ranked 150th in the world, Emma Raducanu entered the US Open with minimal expectations. She stormed through the tournament without dropping a set and became the first qualifier in history to win a Grand Slam—an instant sensation in the tennis world.

8. Appalachian State Beats Michigan (2007)

In American college football, FCS team Appalachian State’s victory over No. 5 ranked Michigan is still considered the greatest upset.

9. Holly Holm Defeats Ronda Rousey (2015)

 But Holly Holm, a former boxing champion, executed a flawless game plan at UFC 193, knocking Rousey out with a head kick in the second round and shaking the sport’s foundation.

10. Denmark Wins Euro 1992

Denmark hadn’t even qualified for Euro 1992. They entered the tournament as late replacements for Yugoslavia. With minimal preparation, they battled their way to the final and stunned reigning world champions Germany to lift the trophy in an unforgettable run.

Betting Markets and the Underdog Factor

In sports betting, underdog stories aren’t just emotionally rewarding—they can be financially rewarding too. Betting markets typically assign long odds to underdogs due to lower expectations of success. However, this also creates value opportunities for savvy punters.

When markets overlook certain factors—like tactical matchups, recent form, or emotional momentum—underdogs may offer tremendous upside. For instance, Leicester City’s title run paid off massively for a handful of bettors who believed in their potential early on. Whether it’s a mispriced fighter, a motivated team with overlooked talent, or strategic conditions favouring the outsider, betting on underdogs is often about reading between the lines.

A site like BetTOM, which offers a wide range of sports and odds formats, allows users to spot these potential mismatches in real time. With careful analysis and a bit of daring, finding value in the unexpected becomes more than just a dream—it becomes strategy.

Underdog moments are the heartbeat of sport. They remind us why we watch, cheer, and sometimes cry with joy. They also provide valuable insights into how narratives, psychology, and performance intersect in real time. For both fans and bettors, they’re a celebration of possibility—the idea that with enough belief and the right circumstances, anything can happen.

Whether you’re placing a wager or just witnessing history unfold, the beauty of the underdog will always have a place in the world of sports.