Atlanta Hawks  center John Collins utilized his length and perfect timing to deny the dunk attempt of Philadelphia 76ers forward Tobias Harris.

After a scramble for the rebound, the ball ended up in Harris' hands. He thought he had a free dunk but then, Collins had other ideas. Watch the slow-mo replay towards the end of the video to see how clean the block is.

The Hawks completed the upset of the Sixers, 130-122. Rookie Trae Young led all scorers with 33 points, to go along with 12 assists and seven rebounds. John Collins himself had 25 points, eight rebounds and two blocks. DeAndre' Bembry chipped in 17 points, six rebounds and four assists from the bench. A total of seven Hawks players logged in double-figures in scoring.

The Sixers, meanwhile, were led by JJ Redick who finished with 30 points including 6-of-13 beyond the arc. Tobias Harris had 21 points and seven rebounds, while Ben Simmons chipped in 15 points, 15 rebounds, eight assists and four steals.

Though they're out of the playoffs, it's still a great win for the Hawks. They proved that they can win against perennial playoff contenders.  The Sixers, meanwhile, need to brush up on their basketball. The playoffs are just around the corner and they'll be facing much tougher teams.