WATCH: Jayson Tatum clanks dunk attempt off back of the rim

Boston Celtics rookie Jayson Tatum has been making us ooh and ah all year long with his highlight-reel dunks, but on Monday night against the Cleveland Cavaliers he suffered an embarrassing miss.

Midway through the first quarter of Game 4, Tatum went up for a one-handed jam as Tristan Thompson closed in on him, and it really looked like he was going to hammer it down.

Unfortunately, he clanked the attempt off the back of the rim, which led to a fast-break opportunity for LeBron James, who converted and got the and-1.

The Cavaliers have an early lead in this pivotal game, up 21-13 at the time of this writing. Tatum and Celtics will need to be sharper going forward, or it’s going to turn into a three-game series as the teams head back to Boston for Game 5.