When underdogs defied expectations and turned the NBA playoffs into unforgettable moments of chaos
Every NBA playoff series begins with a prediction.
The higher seed is supposed to win. The deeper roster, the MVP candidate, the championship favorite, all the numbers usually point in one direction.
And most of the time, the predictions are correct.
But every so often, the playoffs deliver something completely unexpected. A team that was supposed to lose refuses to cooperate with the script. A heavy favorite collapses. And suddenly the basketball world is watching one of the most shocking series in league history.
These moments are what make the NBA playoffs unforgettable.
Over the decades, several underdog teams have stunned the league by defeating opponents that seemed almost unbeatable.
Here are eight playoff upsets that shocked the basketball world and changed NBA history.
1. Golden State Warriors vs Dallas Mavericks (2007)
When the 2007 NBA playoffs began, the Dallas Mavericks looked nearly unstoppable.
They had just finished the regular season with 67 wins, the best record in the league. Led by reigning MVP Dirk Nowitzki, the Mavericks were widely expected to make another deep championship run.
Their first round opponent seemed like little more than a formality.
The Golden State Warriors had entered the playoffs as the 8th seed, barely securing a postseason spot with a 42–40 record. On paper, the matchup looked completely lopsided.
But the Warriors had something the Mavericks struggled to handle: speed, confidence, and a fearless style of play.
Powered by the electrifying energy of Oracle Arena and the leadership of guard Baron Davis, Golden State played with relentless intensity. Their fast paced offense and aggressive defense disrupted Dallas’ rhythm throughout the series.
What followed stunned the basketball world.
The Warriors defeated the Mavericks 4–2, becoming the first 8th seed in NBA history to eliminate a 67 win team in the first round.
The upset became one of the defining moments of the modern NBA playoffs, a reminder that once the postseason begins, even the most dominant regular season teams are never completely safe.
2. Denver Nuggets vs Seattle SuperSonics (1994)
In 1994, the Seattle SuperSonics entered the playoffs as one of the league’s most dominant teams.
They had finished the regular season with 63 wins, the best record in the NBA, and featured a powerful lineup led by stars like Gary Payton and Shawn Kemp. With their aggressive defense and explosive athleticism, Seattle looked like a legitimate championship contender.
Their first round opponent seemed unlikely to cause much trouble.
The Denver Nuggets had entered the playoffs as the 8th seed, making their postseason appearance with a young roster that lacked the experience of most contenders.
But Denver refused to be intimidated.
Led by defensive anchor Dikembe Mutombo and the scoring of guard Mahmoud Abdul-Rauf, the Nuggets played with remarkable resilience throughout the series. After falling behind early, Denver rallied and pushed the matchup to a decisive Game 5.
What happened next became one of the most iconic moments in NBA playoff history.
The Nuggets stunned Seattle, completing a 3–2 series victory and becoming the first №8 seed ever to defeat a №1 seed in the NBA playoffs.
The image of Mutombo lying on the court, clutching the basketball in celebration after the final buzzer, remains one of the most unforgettable scenes in postseason history.
The upset proved that in the NBA playoffs, even the most dominant teams can fall when the pressure rises.
3. Detroit Pistons vs Los Angeles Lakers (2004)
Few NBA Finals matchups have ever looked as one sided on paper as the 2004 championship series.
The Los Angeles Lakers entered the Finals with a roster loaded with superstar talent. Alongside the dominant duo of Shaquille O’Neal and Kobe Bryant, the team had added two future Hall of Famers, Karl Malone and Gary Payton, in pursuit of another championship.
Most analysts expected the Lakers’ firepower to overwhelm their opponent.
The Detroit Pistons, meanwhile, relied on a very different formula. Rather than superstar scoring, Detroit built its identity around relentless defense, teamwork, and disciplined execution.
Led by floor general Chauncey Billups and defensive anchor Ben Wallace, the Pistons turned every game into a physical battle that disrupted the Lakers’ rhythm.
What followed shocked much of the basketball world.
Instead of a competitive series dominated by Los Angeles, Detroit controlled the matchup from start to finish. The Pistons defeated the heavily favored Lakers 4–1, winning the franchise’s third NBA championship.
Billups was named Finals MVP, and Detroit’s victory became one of the most stunning Finals upsets in league history.
The series proved that even a team filled with superstar names can be defeated by discipline, defense, and collective chemistry.
4. Portland Trail Blazers vs Philadelphia 76ers (1977)
When the 1977 NBA Finals began, most observers expected the Philadelphia 76ers to win the championship.
Philadelphia had one of the most exciting players in basketball: Julius Erving, whose spectacular scoring and athletic style had already made him a superstar. The 76ers were experienced, talented, and widely viewed as the stronger team.
Their opponent, the Portland Trail Blazers, were appearing in the Finals for the first time in franchise history.
Early in the series, the predictions seemed accurate. Philadelphia won the first two games and quickly took a 2–0 series lead, putting Portland in a difficult position.
But the Blazers refused to collapse.
Led by the brilliant all-around play of center Bill Walton, Portland began to control the pace of the series. Walton’s passing, rebounding, and defensive presence transformed the Blazers into a cohesive and confident team.
Portland responded with an incredible run, winning four consecutive games to capture the championship.
Walton was named NBA Finals MVP, and the Blazers completed one of the most dramatic turnarounds in Finals history.
The victory remains one of the most memorable underdog stories in NBA history, proof that even a team trailing early in the Finals can rewrite the entire narrative of a championship series.
5. Houston Rockets Championship Run (1995)
Entering the 1995 NBA playoffs, the Houston Rockets did not look like a typical championship contender.
The defending champions had struggled during the regular season and finished with just 47 wins, earning the sixth seed in the Western Conference. No team seeded that low had ever won an NBA title.
But the Rockets still had one enormous advantage: the dominance of center Hakeem Olajuwon.
Olajuwon delivered one of the greatest postseason performances in basketball history. Throughout the playoffs he consistently outplayed some of the league’s best big men, including David Robinson, who had just won the NBA MVP award.
Houston’s playoff journey became a gauntlet of elite opponents.
The Rockets defeated the Utah Jazz, the Phoenix Suns, and the San Antonio Spurs before reaching the NBA Finals against the Orlando Magic, led by rising stars Shaquille O’Neal and Anfernee Hardaway.
In the Finals, Houston completed the remarkable run by sweeping Orlando 4–0.
Olajuwon was named Finals MVP, and the Rockets became the lowest seeded team in NBA history to win a championship.
Their incredible playoff run proved that when a superstar reaches his peak at the right moment, even a lower seeded team can conquer the entire league.
6. New York Knicks Finals Run (1999)
The 1999 NBA season was unusual from the very beginning.
Because of a lockout that shortened the schedule to just 50 games, the regular season felt unpredictable, and many teams struggled to establish consistent momentum. When the playoffs began, the New York Knicks entered as the 8th seed in the Eastern Conference, barely securing a postseason spot.
Historically, that position offered little hope of a deep playoff run.
But the Knicks quickly proved they were far more dangerous than their record suggested.
In the first round, New York stunned the top seeded Miami Heat thanks to a dramatic series clinching shot by Allan Houston in Game 5. The upset immediately captured national attention.
The Knicks continued their improbable run by defeating the Atlanta Hawks and the Indiana Pacers, powered by the aggressive scoring of Latrell Sprewell and the leadership of veteran center Patrick Ewing.
By the time New York reached the championship series, they had already achieved something unprecedented.
The Knicks became the first №8 seed in NBA history to reach the Finals, completing one of the most unlikely playoff runs the league had ever seen.
Although their Cinderella story ultimately ended with a Finals loss to the San Antonio Spurs, the Knicks’ remarkable journey remains one of the most inspiring underdog stories in NBA playoff history.
7. Memphis Grizzlies vs San Antonio Spurs (2011)
In 2011, the San Antonio Spurs entered the playoffs as the top seed in the Western Conference.
Led by veterans such as Tim Duncan, Tony Parker, and Manu Ginóbili, the Spurs were widely considered one of the most disciplined and consistent teams in the league.
Their first round opponent appeared unlikely to threaten them.
The Memphis Grizzlies had entered the postseason as the 8th seed, making just the fourth playoff appearance in franchise history. Few analysts predicted they would pose a serious challenge to the experienced Spurs.
But Memphis brought a physical, defensive style of play that perfectly suited the intensity of the playoffs.
Powered by dominant performances from Zach Randolph and the defensive presence of Marc Gasol, the Grizzlies repeatedly outworked San Antonio in the paint.
Memphis ultimately defeated the Spurs 4–2, becoming only the fourth №8 seed to eliminate a №1 seed in NBA playoff history.
The series marked the beginning of Memphis’ famous “Grit and Grind” era, and it demonstrated once again that the NBA playoffs are never completely predictable.
8. Miami Heat vs. Milwaukee Bucks (2023)
Entering the postseason, the top-seeded Milwaukee Bucks had the league’s best record and one of the NBA’s strongest defenses, led by two-time MVP Giannis Antetokounmpo. The Miami Heat, meanwhile, had needed the play-in tournament just to reach the playoffs. What followed was one of the most improbable first-round upsets in NBA history.
Miami beat Milwaukee 4–1, with Jimmy Butler averaging 37.6 points per game while shooting 59.7% from the field and 44.4% from three. The Heat also shot roughly 45% from three as a team across the five-game series, an extraordinary jump from their 34.4% regular-season mark.
Butler’s 56-point Game 4 and 42-point Game 5 capped a series in which Miami repeatedly erased Milwaukee leads, including a 16-point fourth-quarter deficit in the clinching game. The Heat became the first team to enter the playoffs through the play-in tournament and then win a playoff series, eventually reaching the NBA Finals.
Why Playoff Upsets Make the NBA Unforgettable
The NBA playoffs are designed to reward the league’s best teams.
Over an 82 game season, the strongest rosters usually rise to the top of the standings. But once the postseason begins, momentum, confidence, and resilience can suddenly shift the balance of power.
That’s why playoff upsets remain some of the most memorable moments in basketball history.
Whether it’s an underdog team eliminating a dominant favorite or a lower seed capturing an improbable championship, these surprises remind fans that the outcome of a series is never guaranteed.
And that unpredictability is exactly what makes the NBA playoffs so compelling.