NBA roundup: Hawks stage 30-point comeback to stun the Celtics
Boston, who were confirmed as having clinched the Eastern Conference's top seed earlier on Monday, appeared to be cruising towards a resounding win after outscoring Atlanta 44-22 in the first quarter.
The Celtics raced into a 30-point advantage midway through the second quarter before Atlanta woke up and began chipping into the Boston lead.
The Hawks kept the rally going into the second half, narrowing the gap further with a 34-22 third quarter before harnessing that momentum into the fourth quarter to complete a dramatic win.
De'Andre Hunter led the Hawks scoring with 24 points, including a decisive three-pointer with 10 seconds remaining that gave Atlanta a four-point cushion and effectively made the game safe.
Hunter was backed with 22 points from Bogdan Bogdanovic while Dejounte Murray finished with 19 points, 15 assists and five rebounds.
Hawks coach Quin Snyder praised the unrelenting support of the Atlanta home crowd in helping drive his team to a remarkable victory.
"Tonight the way we started the game, and the way Boston started, their energy really gave us a lift," Snyder said of the Atlanta fans.
"Anytime you're down that much you have to have something out of the ordinary a little bit to get back in the game, and when you have a group of people you know who are behind you thick or thin, rain or shine - and there was a lot of rain early - they were a big part of helping the sun come out tonight."
Atlanta improved to 32-39 and remain in 10th place in the East, on course for a spot in the play-in tournament.
'A good lesson'
Celtics coach Joe Mazzulla said his team paid the price for not killing the game off, adding that Atlanta's physicality had caused his team problems in the second half.
"It's a good lesson," Mazzulla said. "Credit to them for battling back.
"I thought their physicality - they were extremely physical as soon as the ball got past half-court. I thought that messed up our offence, and they made us work for everything."
Celtics star Jayson Tatum had no excuses after the defeat.
"It's tough, you won't win every game you play," Tatum said. "We were up a lot but we didn't do the things we needed to do to win.
"The key is to not over-react. Take it on the chin and get ready for (the next game)."
Elsewhere, Donte DiVincenzo put on a three-point shooting clinic to finish with a career-best 40 points as the New York Knicks kept rolling towards the post-season with a 124-99 blowout against the league-worst Detroit Pistons.
DiVincenzo drained 11-of-20 from outside the arc, just three away from Klay Thompson's single-game record of 14 set in 2018.
Jalen Brunson added 28 points as the Knicks improved to 43-28 to remain fourth in the East.
In San Antonio, Phoenix Suns duo Kevin Durant and Devin Booker combined for 65 points but it was not enough to prevent the Spurs from snatching an upset 104-102 win.
Jeremy Sochan and Devin Vassell each finished with 26 points as Western Conference basement club San Antonio claimed only their 16th win of the season.
At the opposite end of the Western Conference, first-placed Denver trounced the Memphis Grizzlies 128-103 to edge closer to the No.1 seeding.
The defending NBA champions went wire-to-wire in an easy win, with Nikola Jokic once again leading the way, with 29 points, 11 rebounds and eight assists.
The Nuggets lead the Western Conference with a 51-21 record, one win clear of second-placed Oklahoma (49-21).
In Salt Lake City, Luka Doncic grabbed his 19th triple-double of the season to finish with 29 points, 12 rebounds and 13 assists as the Dallas Mavericks outgunned the Utah Jazz 115-105.