In sports, nothing captures the imagination like an upset. Bettors live for those rare moments when the impossible becomes reality and underdogs defy every oddsmaker’s projection. For sportsbooks, it can mean massive windfalls or catastrophic losses. For fans, it’s a reminder of why the games are played in the first place—because no outcome is guaranteed.

From shocking Super Bowl triumphs to Olympic miracles and once-in-a-lifetime knockouts, the biggest betting upsets not only defied probability but also reshaped how sportsbooks and gamblers viewed risk. Here are the Top 10 biggest betting upsets in history, counted down from #10 to #1.

10. Villanova Stuns Georgetown – 1985 NCAA Title Game

• Odds: +900 (9-to-1 underdog)

The Georgetown Hoyas were a juggernaut, led by Patrick Ewing and fresh off a dominant season. Villanova entered the championship game as a massive underdog, needing a near-perfect performance to compete.

The Wildcats delivered just that, shooting over 78% from the field to secure a 66-64 victory. Bettors backing Villanova at 9-to-1 odds cashed in, while fans witnessed one of the greatest NCAA Tournament upsets ever.

Villanova vs. Georgetown: 1985 National Championship | FULL GAME

9. Greece Wins Euro 2004

• Odds: +8000 (80-to-1 underdog)

International soccer is filled with surprises, but nothing matched Greece’s unlikely run in 2004. Written off before the tournament, Greece upset France, the Czech Republic, and finally Portugal in the final.

Bettors who saw value in the disciplined Greek side cashed in at 80-to-1 odds. The victory remains one of the biggest upsets in European football history, proving that tactics and heart can overcome raw talent.

Greece ● Road to Victory – EURO 2004

8. Rulon Gardner Beats Aleksandr Karelin – 2000 Olympics Wrestling

• Odds: Estimated +2000

Aleksandr Karelin was a Greco-Roman wrestling legend, undefeated for 13 years and a three-time Olympic gold medalist. Rulon Gardner, a dairy farmer from Wyoming, wasn’t expected to win a single point.

In Sydney, Gardner shocked the world by outlasting Karelin 1-0. Though sportsbooks didn’t heavily list Olympic wrestling, the implied odds were enormous. It remains one of the greatest individual upsets in Olympic history.

USA’s Rulon Gardner stuns undefeated “Russian Bear” Aleksandr Karelin in Olympic epic | NBC Sports

7. New York Jets Beat Baltimore Colts – Super Bowl III (1969)

• Odds: +1800 (18-to-1 underdog)

The Baltimore Colts entered Super Bowl III as heavy favorites, hailed as one of the greatest NFL teams ever. The Jets, led by brash quarterback Joe Namath, were written off as AFL upstarts.

Namath guaranteed victory and delivered, guiding New York to a 16-7 shocker. At nearly 20-to-1 odds, Jets backers celebrated both a betting windfall and the legitimization of the AFL, paving the way for the modern NFL.

Super Bowl III Highlights

6. Holly Holm Knocks Out Ronda Rousey – UFC 193 (2015)

• Odds: +900 (9-to-1 underdog)

Ronda Rousey was the face of MMA, unbeaten and considered invincible. Holly Holm, a former boxer, was seen as a respectable but overmatched challenger.

Holm dismantled Rousey with striking precision before landing a devastating head kick knockout in Round 2. The upset not only stunned fight fans but also paid bettors handsomely at 9-to-1 odds, signaling the end of Rousey’s dominance.

Holly Holm vs Ronda Rousey Highlights (Holm Shocks The World) #ufc #rondarousey #hollyholm #mma

5. Appalachian State Stuns Michigan – 2007

• Odds: +2000 to +2500

College football is notorious for mismatches early in the season, but no one expected Appalachian State, an FCS team, to beat No. 5 Michigan at The Big House.

The Mountaineers not only kept the game close but blocked a last-second field goal to win 34-32. Bettors who had the courage to back Appalachian State were rewarded with payouts at around 20-to-1. This game changed how sportsbooks approached college mismatches forever.

4. Rich Strike Wins the Kentucky Derby – 2022

• Odds: +8000 (80-to-1 underdog)

The Kentucky Derby is known for longshots, but Rich Strike’s triumph shocked even veteran horse racing bettors. Entering the race as an alternate, he wasn’t expected to even run until the day before.

Breaking from the far outside post, Rich Strike stormed through the field in the final stretch to claim victory. Bettors who placed even small wagers at 80-to-1 odds cashed in huge. It was the second-biggest longshot win in Derby history.

Story of Rich Strike’s historic win at 2022 Kentucky Derby | NBC Sports

3. Miracle on Ice – USA Beats Soviet Union (1980 Winter Olympics)

• Odds: +1000 to +1200

The Soviet Union had dominated international hockey for decades, winning four straight Olympic gold medals. The young U.S. team, made up of college players, was expected to be little more than a speed bump.

Instead, Herb Brooks’ squad played with relentless energy. A late goal by Mike Eruzione sealed a 4-3 victory that sent shockwaves around the world. At 10-to-1 odds, bettors who believed in the miracle cashed in big.

2. Buster Douglas Defeats Mike Tyson – 1990

• Odds: +4200 (42-to-1 underdog)

Mike Tyson entered Tokyo as the undefeated, undisputed heavyweight champion and the most feared man in boxing. Oddsmakers gave James “Buster” Douglas virtually no chance—he was a massive 42-to-1 underdog.

Yet Douglas fought the fight of his life. After weathering a knockdown in Round 8, he stunned Tyson with a furious combination in Round 10 that floored the champion. The knockout reverberated across the globe and remains boxing’s greatest upset.

Mike Tyson vs. Buster Douglas

1. Leicester City’s 5000-to-1 Crown – The Ultimate Betting Miracle

• Odds: +50000 (5000-to-1)

At the start of the 2015-16 English Premier League season, Leicester City wasn’t expected to avoid relegation, let alone win the title. Bookmakers listed them at a staggering 5000-to-1.

Behind Jamie Vardy’s scoring streak and Claudio Ranieri’s leadership, Leicester stunned the world. Bettors who placed even a small wager—£10 or $20—walked away with thousands. It remains the greatest longshot triumph in modern team sports history and the ultimate nightmare for sportsbooks.

Leicester City Road to PL Victory 2015/16 | Cinematic Highlights |

Conclusion

Sports betting thrives on unpredictability, and nothing highlights that more than legendary upsets. Whether it’s Douglas knocking out Tyson, Leicester City winning the Premier League, or the U.S. hockey team toppling the Soviets, these moments prove that odds are not destiny. For bettors, they’re thrilling reminders that even the smallest wager can pay off big when history is on your side.

At the end of the day, these upsets are why fans love sports—they embody hope, possibility, and the undeniable fact that on any given day, miracles can and do happen.