Few moments in sports are as exciting as major upsets. America loves the underdog, and when David slays Goliath, the story lingers in our minds long after the games are played.
Throughout its history, the NBA has seen its share of memorable playoff upsets.
Whether it's an eighth seed beating a No. 1 seed in the first round, or a young and inexperienced team knocking off a defending champion in the NBA Finals, basketball provides some of the best drama in all of sports.
The NBA went from a best of five series, to a best of seven series in the first round starting in the 2002-03 season. Since then there have been fewer upsets, but it makes the ones that did happen more special.
Without further ado, let's look at the 25 biggest postseason upsets in NBA history.
Nicholas Goss is an NBA and Oklahoma City Thunder Featured Columnist, follow him on Twitter.
The Los Angeles Lakers steamrolled through the Western Conference playoffs in 1989, sweeping every series to earn a rematch with the Detroit Pistons in the NBA Finals.
Los Angeles had beaten the Pistons in seven games the year before in the Finals, but the Pistons were too good for the Lakers in 1989.
Led by Isiah Thomas and Joe Dumars, the Pistons swept the Lakers from the Finals and captured the franchise's first-ever NBA title.
This upset happened Friday night, and while the No. 1 seed Spurs were beaten by the eighth-seeded Grizzlies in six games, it's not one of the all-time upsets.
The Grizzlies were a bad matchup for the Spurs. San Antonio couldn't handle the Memphis big men, as Marc Gasol and Zach Randolph dominated offensively in the series.
The Memphis guards played very well despite their inexperience, and former Celtic and Finals winner Tony Allen played amazing defense on Spurs guard Manu Ginobili.
The Grizzlies were many people's upset special of the first round, but it was a very good upset nonetheless.
They will play the Oklahoma City Thunder in the next round.
Led by Chris Mullin (pictured) and Tim Hardaway, the high-scoring Warriors defeated the David Robinson-led San Antonio Spurs in the first round of the 1991 postseason.
The Warriors, who many predicted would be easily dealt with by the defensively-talented Spurs, overcame San Antonio 3-1.
The Houston Rockets defeated the NBA’s rising power, the Orlando Magic, in just four games in the 1995 NBA Finals.
After an overtime win in Game 1 on a Hakeem Olajuwon tip-in in the final seconds, the Rockets took the next three games rather easily to win their second consecutive championship.
The Magic were led by Penny Hardaway and a young Shaquille O’Neal, and made it to the Finals earlier than experts had anticipated.
Unfortunately, this was the last time the Magic tandem of Shaq and Penny ever made the Finals together.
Led by NBA legend Elvin Hayes, the Washington Bullets defeated the favored Philadelphia 76ers in the 1978 East Finals.
The 76ers were the defending conference champs, having lost to Portland in the 1977 Finals.
After defeating the 76ers, the Bullets would go on to win the franchise’s first and only NBA title.
The Los Angeles Clippers last won a playoff series when they defeated the third-seeded Denver Nuggets in the first round of the 2006 playoffs.
Led by Sam Cassell and Elton Brand, the Clippers defeated the explosive Nuggets, led by superstar Carmelo Anthony.
The Golden State Warriors’ only NBA title came in 1975 when they swept the heavily-favored Bullets in four games.
Rick Barry led the way for the Warriors with his great scoring.
The sixth-seeded Rockets made this list earlier, and they’ll make one more appearance after this.
Going up against the No. 1 seeded Spurs in the West Finals, the Rockets beat their Texas rivals rather easily.
In a matchup versus 1995 NBA MVP David Robinson, Rockets center Hakeem Olajuwon dominated the Spurs center and gave a legendary series performance that will be remembered for a long time (see video).
The young Phoenix Suns of 1976 defeated the defending champion Golden State Warriors in the West Finals to advance to the franchise’s first NBA Finals.
The Warriors have never returned to the conference finals, and the Suns wouldn't reach the NBA Finals again until 1993.
The Suns were defeated by the Boston Celtics in the Finals in six games, including a triple overtime thriller in Game 5, which Boston won.
The Utah Jazz had a remarkable 1988 season, losing to the eventual champion Lakers in the West semifinals. They came into 1989 with high hopes and had a great regular season.
But they were beaten by the Warriors 3-1 in the first round of the playoffs. It was one of the many times NBA Hall-of-Famers John Stockton and Karl Malone failed to win a championship.
We’ve all seen how this series ended. Michael Jordan’s last-second shot over Cavaliers guard Craig Ehlo is one of the most memorable moments in NBA history and was one of Jordan’s first great playoff moments.
Jordan led the Bulls to a 3-2 series win over a balanced and fundamentally-sound Cavaliers team.
In the lockout-shortened 1999 NBA season, the eighth-seeded New York Knicks defeated the experienced and playoff-tested Indiana Pacers in the East finals to become the only eighth-seed to ever make the NBA Finals.
The series is best remembered for Knicks forward Larry Johnson’s epic four-point play in Game 3, which is also one of the most controversial fouls in recent playoff memory.
The 1995 Rockets are back on this list, and their semifinal win over the Phoenix Suns is one of the most memorable ever.
In a hotly-contested series between two rivals, the Rockets defeated the Suns in seven games, clinching on the road.
Mario Elie’s late three-pointer sealed the deal for the Rockets and ended Charles Barkley’s last great chance for an NBA title.
The Dallas Mavericks were one of the league’s rising young teams in 1987, but saw their very good season cut short with a first-round upset by the Seattle Supersonics.
Led by deadly scorers Tom Chambers and Xavier McDaniel, the Sonics defeated the heavily-favored Mavericks 3-1.
The 1987 Sonics are one of the few teams to win a playoff series after having a losing regular-season record.
After being swept in the conference finals the year before, the 1990 Phoenix Suns defeated the heavily-favored Lakers in the West semis to advance to the conference finals again.
Led by Tom Chambers and Kevin Johnson, the Suns' high-scoring offense proved too much for the aging Lakers.
After upsetting the Miami Heat in the 1998 playoffs, the Knicks looked to do the same in 1999.
The eighth-seeded Knicks overcame the Heat in Game 5 with a very good performance by Allan Houston.
It was Miami’s last title threat of the Tim Hardaway and Alonzo Mourning era. Without Jordan to defeat, who had retired prior to the season, Miami missed a golden chance to win the franchise’s first NBA title.
The inexperienced Houston Rockets defeated Kareem Abdul-Jabbar and the defending champion Lakers in the 1981 Western Conference first round en route to an NBA Finals appearance against Boston.
Rockets center Moses Malone led the way against Abdul-Jabbar and had a splendid series both offensively and defensively.
The 1977 Portland Trail Blazers are one of the youngest champions ever, led by Finals MVP Bill Walton to a six-game victory against the talented and heavily-favored Philadelphia 76ers.
The triumph was the only time the Blazers have won the NBA title; they lost in the 1990 and 1992 Finals.
The 1969 Celtics were an old team that was nearing the end of their dynasty.
They limped into the playoffs and defeated the Knicks en route to yet another NBA Finals against a familiar opponent in the Los Angeles Lakers, led by Jerry West and Elgin Baylor.
After a dramatic Game 6 win on a last-second shot by Sam Jones, the Celtics forced a deciding Game 7.
Boston won Game 7 with a great performance by Bill Russell, who motivated his players before the game by giving them a handout of the Lakers’ owner’s plans for L.A.'s postgame title celebration.
The Knicks upset the heavily-favored Heat in the first round of the 1998 East playoffs in five games. It was a very physical series, and the two teams made for a very good rivalry in the late 1990's.
In Game 4 at Madison Square Garden, Heat center Alonzo Mourning and Knicks head coach Jeff Van Gundy were involved in an altercation with Van Gundy holding onto Mourning's leg while on the ground.
The skirmish resulted in Mourning being suspended for the deciding Game 5, which the Knicks won in Miami to upset the Heat.
The Heat were a very good team, having won 55 games that season, good for second in the East.
The Los Angeles Lakers added Gary Payton and Karl Malone in the offseason to bolster their squad in 2004 and help the two of them win their first-ever NBA titles.
With Shaq and Kobe Bryant still together, the Lakers made the NBA Finals, but were easily beaten in five games by the Detroit Pistons.
The Pistons were led by point guard and series MVP Chauncey Billups, as well as two-time Defensive Player of the Year, center Ben Wallace.
Malone would retire after the series. Payton kept playing in search of his first championship, which he would win with the Miami Heat in 2006.
The series was the last NBA Finals appearance for Shaq and Kobe in Los Angeles. Shaq would be traded to Miami about a month later, while Kobe has remained with the Lakers to this day.
The Philadelphia 76ers ended years of playoff disappointment in 1983 by winning the NBA Finals in a 4-0 sweep of the Los Angeles Lakers.
However, they found real difficulty in their title defense the next season against the New Jersey Nets.
After losing the first two games of the series at home, the 76ers won both games in New Jersey to force a deciding Game 5.
Led by Michael Ray Richardson, the Nets would win Game 5 101-98 to eliminate the defending champions.
The Nets would lose to the Milwaukee Bucks in the next round, and the 76ers would not make the Finals again until 2001.
After losing the 2006 NBA Finals to the Miami Heat, the Dallas Maverick won 67 games in 2007. Mavericks forward Dirk Nowitzki was the NBA MVP, and Dallas looked poised for another march to the Finals.
But the Golden State Warriors had other plans, defeating the Mavericks in six games.
Baron Davis led the way for the Warriors by providing good scoring and leadership.
Warriors coach Don Nelson was impressed with his team’s defensive effort all series, and in the deciding Game 6, the Warriors held Nowitzki to 2-of-13 shooting to advance to the second round of their first playoff appearance in 13 years.
The Los Angeles Lakers cruised through the 1986 playoffs and were the overwhelming favorites in a West finals rematch against the young Houston Rockets.
The defending champs beat the Rockets in Game 1, but lost the next three games. Rockets center Hakeem Olajuwon dominated the Lakers both offensively with his scoring and defensively with his many blocked shots.
In Game 5 the Lakers jumped out to an early lead at home, but the Rockets climbed back into the game.
In the final seconds, Rockets forward Ralph Sampson made an unbelievable shot as time expired to end the Lakers' title defense and earn a trip to the NBA Finals against Boston.
Most basketball experts thought the Rockets were too young to compete for a title, but they proved they were ready with a great upset of the talented Lakers.
Unfortunately, it was the last time the Rockets would make a deep playoff run in the 1980's; Sampson was plagued by many injuries, and several players got involved in drugs.
The 1994 Seattle Sonics had the best record in the league at 63-19, as well as the best home and away record.
Without Michael Jordan leading the Bulls, and coming off a deep playoff run the year before, the Sonics looked ready to take the next step and make the Finals.
But they ran into an athletic, young and defensively strong Nuggets squad, led by center Dikembe Mutombo.
After easily winning the first two games at home, Seattle looked like they would sweep the Nuggets and move on to the second round.
The Nuggets won the next two games at home by dominating the paint defensively, led by Mutombo and his plethora of blocked shots. On offense, the Nuggets slowed down the pace of the game and were not rattled by the Sonics' full-court press.
Denver won the deciding Game 5 in Seattle 98-94 in overtime to become the first eighth-seeded team to upset a one-seed since the NBA Playoffs format changed in 1984.
The Nuggets almost upset the Utah Jazz in the next round, but lost in seven games.