Parity has become a defining theme in recent NBA playoffs, and nothing illustrates that better than the surge in major series upsets.
Across the 2025 and 2026 postseasons, four NBA betting underdogs priced at +425 or longer have gone on to win their series outright. According to the Sports Odds History database (tracking results since 1985), those rank among the biggest playoff upsets ever recorded.
Here’s a look at the full list of the largest upsets in NBA playoff history:
List of Biggest Series Upsets in NBA Playoffs
| Year | Round | Underdog | Odds | Favorite | Odds |
|---|---|---|---|---|---|
| 1994 | Round 1 | Nuggets | +1400 | SuperSonics | -2000 |
| 2007 | Round 1 | Warriors | +1200 | Mavericks | -1800 |
| 2012 | Round 1 | 76ers | +900 | Bulls | -1400 |
| 2020 | Round 2 | Nuggets | +850 | Clippers | -1300 |
| 2026 | Round 1 | 76ers | +800 | Celtics | -1300 |
| 2023 | Round 1 | Heat | +750 | Bucks | -1200 |
| 1989 | Round 1 | Warriors | +700 | Jazz | -1000 |
| 2025 | Round 2 | Knicks | +550 | Celtics | -800 |
| 2009 | Eastern Conference finals | Magic | +550 | Cavaliers | -700 |
| 1990 | Round 2 | Suns | +500 | Lakers | -700 |
| 2004 | NBA Finals | Pistons | +500 | Lakers | -700 |
| 2011 | Round 1 | Hawks | +425 | Magic | -650 |
| 2026 | Round 1 | Lakers | +425 | Rockets | -550 |
| 2025 | Round 2 | Pacers | +425 | Cavaliers | -550 |
| 2016 | Round 1 | Trail Blazers | +415 | Clippers | -525 |
What is the Biggest Upset in NBA Playoff History?
Based on the pre-series betting odds, the Denver Nuggets are responsible for the biggest upset in NBA playoff history. They were +1400 underdogs when they knocked off the Seattle Supersonics in Round 1 of the 1994 postseason.
The Nuggets were the No. 8 seed, earning a 3-2 series win over the No. 1 SuperSonics, who were -2000 favorites in Round 1.
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