The 2016-17 Boston Celtics were an improbable team in many ways.
They finished with the best record in the Eastern Conference despite lacking a true "superstar," as Isaiah Thomas, Avery Bradley and Al Horford led Brad Stevens' plucky club.
And on this date three years ago -- May 21, 2017 -- they took down the defending champions with an improbable victory.
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Facing a 2-0 deficit entering Game 3 of the Eastern Conference Finals against LeBron James and Kyrie Irving's Cavaliers, the Celtics went on the road and upset Cleveland 111-108 in dramatic fashion.
Here's how it ended: Bradley's 3-pointer rattled around the rim before falling to break a 108-108 tie with just 0.1 seconds left.
The Celtics lost the next two games of the series to bow out in five games, but their impressive Game 3 win characterized the resolve that made the 2016-17 squad special.
Here are two other notable May 21 performances from the C's, who are 5-2 all-time in games played on this date:
Boston Celtics
May 21, 2002: Antoine Walker scores 26 points on a game-high 32 attempts -- the fewest points of any player in Celtics playoff history who attempted at least 32 shots -- as the C's tie the Eastern Conference Finals against the New Jersey Nets in a 93-86 win.
May 21, 1987: Isiah Thomas leads all scorers with 36 points, but Larry Bird's near-triple double (31 points, nine rebounds, 12 assists) carries the day as the Celtics open up a 2-0 East Finals lead over the Detroit Pistons.