Jaylen Brown Upset After Fourth-Quarter Celtics Crumble Vs. Cavs

The Boston Celtics took a complete 180-degree turn when entering the fourth quarter with a 16-point lead over the Cleveland Cavaliers on Tuesday night.

Coming fresh off a historic 140-88 blowout win against the Golden State Warriors on Sunday, the Celtics were in search of a 12th consecutive trip to the win column. And for the most part, Boston did everything possible to ensure that would happen. The C's extended their lead to 22 points in the fourth quarter, however, amid an uncharacteristic, ice-cold shooting slump at the worst time, the Cavaliers countered and made it out with a 105-104 win.

Rather than chalking up the loss as some much-needed learning lesson, Jaylen Brown didn't shy away from the reality of the team failing to keep its foot on the gas, especially against a Donovan Mitchell-less Cavs squad.

"Today matters," Brown told reporters, according to Adam Himmelsbach of The Boston Globe. "Whether everybody wants to throw it away or not, we've got to look at the film and address some stuff, because that matters."

At first glance, a one-point loss after winning 11 in a row while also still leading the NBA in total wins (48) doesn't seem like anything to be worried about. However, Boston isn't in the same position as the majority of teams across the league. Jayson Tatum and Brown have proven capable of leading a dominant regular season run, but that doesn't matter.

Boston entered the contest with just one loss while leading by 10-plus points at halftime through a 60-game span.

It'd be disingenuous to call Tuesday night's loss anything but what it was: a reality check. Sure, for 90-plus-percent of the season, the Celtics have been flawless; offensively, defensively and even second-year head coach Joe Mazzulla has made all the right moves regarding the rotations. But none of that matters come playoff time and those 48 wins don't carry over. Boston can still lose any given night, even if at full strength and if an opponent doesn't have its star player available.

In the fourth quarter, the Celtics didn't show up. The team shot 8-of-25 from the floor, including 0-for-8 from three. Tatum missed the potential game-winning fadeaway jumper over two Cleveland defenders, which initially drew a foul call that was then overturned upon further review. Then again, had Boston collectively done its job and put the Cavs away early by preserving its double-digit lead, no blame would fall on Tatum's shoulders.

"Just hope to bounce back from tonight," Tatum told reporters, per NBC Sports Boston. "There's a lot of things that we know we can clean up, and (we) didn't necessarily play like ourselves (in) the second half. And this year we've done a really good job at responding so I look forward to us playing better and responding on Thursday."

The Celtics, this season more than any other under the Tatum-Brown era, need to tread carefully. Ownership and the front office admittedly had no intensions of bringing back last season's group after identifying the past two seasons as failures of what the organization is looking to accomplish.

Boston still owns the No. 1 seed in the Eastern Conference, it still holds more wins than any other team and most importantly, everyone is still healthy. But even despite all of that, vulnerabilities can make themselves known as the most inconvent of times, and that applies to losses in March to the Cavaliers, and remains prevalent once the playoffs begin as well.