1) Bucks over Suns, 1978

With the ABA merger inflating the NBA to 22 franchises, the league expanded the playoffs as well in 1977, going from five playoff teams per conference to six. The two division winners received byes, while the #3 through #6 seeds played in best-of-three first round series. This first round format lasted for seven years and the only major upset happened in 1978, when the #6 seed Bucks upended the #3 seed Suns. It was a prime example of how a best-of-three series can seamlessly shift to the underdog and it’s surprising it didn’t happen more often. Marques Johnson took over the two-game sweep for Milwaukee, dropping 57 total points on 59.5% shooting. The Suns conversely struggled, shooting just 42.9% from the field as a team and were eliminated so quickly they barely made a blip. The Bucks almost upset the #2 seed Nuggets in the next round but lost in seven games. Phoenix returned strong in the 1979 playoffs, reaching the Western Conference Finals.

2) Nets over 76ers, 1984

Moses Malone’s infamous “fo’, fo’, fo’” 1983 playoff prediction would have been a lot less sonorous a year later. Under the new format starting in 1984, it would be “three, fo’, fo’, fo’.” It also would have been vastly incorrect this time, as not only did the 76ers fail to sweep the Nets in the first round, the defending champs were victims of one of the biggest upsets in playoffs history. Led by former 76ers castoff Darryl Dawkins battling against Malone and dynamic point guard Micheal Ray Richardson running circles around Maurice Cheeks, the Nets set the tone early, winning games one and two in Philadelphia by 15 points and 14 points, respectively. The Sixers seemingly righted the ship with two consecutive wins in New Jersey to tie the series, but it was just a prelude to a devastating game five loss. New Jersey lost in the second round and it took 18 years for them to win another playoff series. The Sixers recouped in 1985 and returned to the Conference Finals one last time with this core group.

3) Warriors over Mavericks, 2007

When the NBA expanded first round series to best-of-seven in 2003, the intention was to give higher seeds an abstract advantage. Tell that to the ’06-’07 Mavericks, who were the defending Western Conference champs, won a franchise record 67 games, and led by soon-to-be-named MVP Dirk Nowitzki. The Warriors were making their first playoff appearance in 13 years, finished just barely above .500 to sneak in as a #8 seed, and had a roster full of veteran castaways. None of that mattered once the games started. Don Nelson’s team put everything together at just the right time, stunning the Mavericks in Dallas in game one, cresting momentum with their “We Believe” rallying cry, and finishing the series in six. It was arguably a career peak for Golden State’s Baron Davis, Stephen Jackson, and Jason Richardson, all of whom dominated their Dallas counterparts. This is maybe the all-time biggest first round upset and it led to the uniquely embarrassing moment of Nowitzki receiving his MVP trophy during halftime of a second round game in which he wasn’t participating.

4) Hawks over Pacers, 1996

They reached the brink of the NBA Finals in 1994 and 1995 and entered this series as the #3 seed, but the Pacers were cautiously optimistic, at best. Reggie Miller had fractured his eye socket in the penultimate regular season game, necessitating surgery and leaving him unavailable indefinitely. Their opponents knew a thing or two about adjusting to life after losing a superstar. Dominique Wilkins had left via free agency before the ’95-’96 season but the savvy, veteran Hawks squad actually improved by four wins in his absence. Their back court duo of Mookie Blaylock and Steve Smith dominated this series, while Rik Smits stepped up his offensive game to keep the Pacers afloat. Miller managed to return for the winner-take-all game five and played impressively through vision issues to score 29 points, 16 of which came in the fourth quarter. But the Hawks held on for an 89-87 victory, with a buzzer beater three-pointer from Miller clanging off the rim.

5) Grizzlies over Spurs, 2011

Expectations were low for the Grizzlies entering the 2011 playoffs. It was their first postseason appearance in five years and they entered as a #8 seed, taking on a dominant Spurs squad with a championship pedigree. In the unofficial start of the “grit n’ grind” era, Memphis stole game one in San Antonio, behind huge performances from Zach Randolph and Marc Gasol. The Grizzlies would never trail in the series, eventually taking a 3-1 lead and then putting it away in six games. Not only was this the first playoff series win in Grizzlies franchise history, they had never even won a postseason game before, getting eliminated in a sweep in their prior three appearances. Memphis was defeated by the Thunder in the second round but turned this into a habit, reaching the playoffs for the next six consecutive years and winning three more series. There was chatter that this possibly signaled the end of the Tim Duncan Spurs title window but that was, of course, unfounded. San Antonio was back in the NBA Finals two years later, with a playoff run that included a revenge victory over Memphis in the Conference Finals.

6) Nuggets over Sonics, 1994

It was the first ever playoff upset by a #8 seed and is arguably still the signature one. It certainly has the most iconic upset imagery, that of Nuggets center Dikembe Mutombo clutching the ball and falling to the ground in celebration at the end of game five. A quarter century later, this is still also arguably the greatest moment in Nuggets franchise history. They were hardly a conventionally successful squad, built around the defensive beast Mutombo and jitterbug point guard Mahmoud Abdul-Rauf. The Nuggets also faced a seemingly impossible task in game five in Seattle against a Sonics team that was thus far 39-4 on their home court that season. Backup point guard Robert Pack was Denver’s surprise hero, leading all scorers with 23 points, taking advantage of a hobbled Gary Payton, who was playing on a recently sprained ankle. Mutombo finished with eight blocks and 15 rebounds, including the final board that clinched the game and triggered his celebratory collapse.

7) Knicks over Heat, 1998
8) Knicks over Heat, 1999

No matter the seeding or circumstances, a Heat-Knicks series in this era was always going to be physical and always come down to the wire. You’d be hard pressed to call these series exciting, especially the latter in which both teams averaged less than 85 points per game. They were certainly eventful though, and remarkable in that the Knicks won both despite being the #7 seed and #8 seed, respectively. It was the conclusion of a trilogy that started in 1997, when the Heat defeated New York in a Conference Semifinals that hinged on several Knicks players getting suspended for leaving the bench during a fight. That was a mere prelude to 1998, when game four devolved into an all-out brawl highlighted by Jeff Van Gundy clinging to Alonzo Mourning’s legs like a helpless koala. Mourning was suspended due to his role in the donnybrook and the Knicks took advantage, easily winning the winner-take-all game five to advance as a #7 seed. Stakes were even higher in 1999 as Michael Jordan’s retirement left the Eastern Conference seemingly wide open. It came down to game five again, with Allan Houston hitting the winning shot for the Knicks for a final score that only a sadist could love, 78-77. The Knicks subsequently defeated the Hawks and Pacers to become the first #8 seed ever to reach the NBA Finals.

“If queried, many longtime Sonics fans would pick this team as their all-time favorite, even more so than the ’78-’79 team that won the championship, and the ’95-’96 team that reached the NBA Finals behind Shawn Kemp and Gary Payton.”

9) 76ers over Bulls, 2012

Every underdog needs at least a little bit of luck to go their way, and #8 seed Philadelphia got a huge dose of fortune in this one. Late in a game one Bulls win, star point guard Derrick Rose fell awkwardly and suffered a torn ACL. It was a demoralizing blow for Chicago and somehow got even worse in game three, when Joakim Noah was sidelined indefinitely with a foot injury. Even with the Sixers ahead 3-1 in the series, the shell-shocked Bulls certainly didn’t quit. They put on a defensive clinic in a 77-69 game five win to stay alive, then pushed the Sixers to the limit in game six in Philadelphia. Andre Iguodala provided just enough offensive spark for the 76ers in that deciding game six, finishing with 20 points and seven assists and hitting the series winning free throws with two seconds left. Though injuries played a huge part here, Philly actually played well in the second round against a fully healthy Celtics, pushing them to seven games. Rose ultimately missed the entire ’12-’13 season due to his injury, and has never fully recovered his MVP-level game since.

10) Warriors over Jazz, 1989
11) Warriors over Spurs, 1991
12) Warriors over Nuggets, 2013

In the 35 years between Rick Barry’s 1978 departure and Stephen Curry’s 2013 breakout season, the Warriors made just seven playoff appearances but pulled off a first round upset in five of them. Golden State entered the 1989 playoffs as a #7 seed but completely outplayed the #2 seed Jazz in a first round sweep. The athleticism and offensive fire power of this Warriors era was on full display, with Chris Mullin and Mitch Richmond combining to average over 58 points per game. By 1991, Golden State had added Tim Hardaway into the mix and the #2 seed Spurs got the full dose of Run-TMC’s potential. The trio’s stats were astounding in this series, averaging a combined 70.9 points, 18.1 rebounds, and 14.3 assists per game to put the Spurs away in four. Less than two weeks later, Run-TMC was finished, as the Warriors lost in the second round to the Lakers and Richmond was traded away in the subsequent offseason. This led to an extended fallow period for the franchise with hope for a turnaround finally arriving in 2013. Led by their new star triad of Curry, Klay Thompson, and Draymond Green, the Warriors pulled off a first round upset over the #3 seed Nuggets, a little appetizer of their eventual three championships and counting.

13) Sonics over Mavericks, 1987

Even considering the ’78-’79 title team, many Sonics fans would still pick this ’86-’87 squad as their all-time favorite. They put together one of the greatest Cinderella runs in NBA playoffs history, pulling off two consecutive series upsets after finishing the regular season with a losing record and the #7 seed. It helps that they were a charming group of eclectic players, like rookie floor general Nate McMillan and paint enforcer Xavier “X-Man” McDaniel. Their first round opponent was a Mavericks team expected by many to challenge the Lakers for West supremacy. Dallas ran the Sonics off the floor in a 151-129 game one victory but things turned around immediately. Mavs star Mark Aguirre was hampered the remainder of the series with strep throat and Seattle’s long range bomber Dale Ellis took over. Having spent his first three seasons languishing on the Mavericks bench, Ellis got his revenge here as a SuperSonic, averaging 32.0 points per game over three straight Seattle wins. They followed it up with an upset of the Rockets before getting swept by the might Lakers in the Conference Finals.

14) Rockets over Lakers, 1981
15) Kings over Trail Blazers, 1981

While the powerhouse Celtics and 76ers were waging an all-timer battle in the Eastern Conference Finals, the West version was the most unlikely matchup in league history. It started with a massive first round upset by the #6 seed Rockets over the defending champion Lakers. Slumming in the first round as the #3 seed due to Magic Johnson missing three months with a knee injury, the Lakers were overconfident, disjointed, and falling apart at the seams behind closed doors. Houston took full advantage, with point guard Calvin Murphy and center Moses Malone arguably outplaying their L.A. counterparts Johnson and Kareem Abdul-Jabbar in 2-1 series upset. On the same night the Rockets finished off the Lakers, the Kings closed out a stunning upset over the Trail Blazers. The seeding was immaterial here, as Kansas City was a #5 seed and Portland a #4. But the Kings had entered the playoffs with a losing record and were 17 years removed from their last playoff series win. Houston and Kansas City followed with second round upsets over the Spurs and Suns, respectively, to set up their improbable Conference Finals, which the Rockets won in a sweep. Fans were apparently ambivalent to these historic runs, as low television ratings hit a new low, inspiring the league to expand first round series to best-of-five to reduce first round upsets.