NBA Finals 2024: The biggest questions after Game 3 of Celtics-Mavericks

Jaylen Brown: Celtics kept their poise down the stretch (0:57)

Jaylen Brown praises his Celtics teammates after a gritty road win in Game 3 after the Mavericks attempted a late fourth-quarter surge. (0:57)

The Boston Celtics are one win from capturing the 2024 NBA title -- and they earned it.

Boston built its fourth-quarter lead to 21 points before a frantic rally by the Dallas Mavericks turned Wednesday's Game 3 into a roller coaster. However, the Celtics withstood every late charge by the Mavericks, who lost superstar guard Luka Doncic in the final minutes after he fouled out on a controversial blocking call, and took a 3-0 lead in the Finals behind a 106-99 victory in Dallas.

The Celtics also won despite big man Kristaps Porzingis being sidelined by a leg injury. His status remains day-to-day, but ESPN's Adrian Wojnarowski reported there is "real doubt" over Porzingis' status moving forward.

How did Boston overcome Porzingis' injury and hold off Dallas' late rally? Are these Finals headed for a Celtics sweep? Our NBA Insiders are breaking down the wild finish to Game 3, Doncic's uneven performance and what lies ahead in Friday's Game 4 (8:30 p.m. ET, ABC).

What was your biggest takeaway from the Celtics' Game 3 win?

Tim Bontemps: That Boston still hasn't quite shaken all of its bad habits but still has enough talent to close out this series. The fourth quarter was a highlight reel of Boston's past issues -- poor offensive execution, lapses in concentration and overall head-scratching decision-making. But after giving up a 22-2 run that got Dallas back within a point, Boston was able to lock in defensively down the stretch. It was enough to move the Celtics one win away from an NBA-record 18th championship -- even if it became far more stressful than it should have been.

Chris Herring: The Celtics are inevitable. It didn't matter that Porzingis wasn't there, because Xavier Tillman could hold his own in his minutes. It didn't matter that Kyrie Irving finally found his offense, because so did Jayson Tatum. It didn't matter that the Mavericks took their biggest lead of the series early in Game 3, because Boston had an otherworldly Jaylen Brown showing in the third quarter and managed to escape after doing just enough to hold off a late, furious Dallas run.

Brian Windhorst: The Celtics are finally over the hump, and they have one hand on banner No. 18. They had to survive their late-game demons, maybe just to make it feel like they earned it. Boston has lost a handful of playoff games in this exact fashion over the past several years, and during that 20-2 run in the fourth quarter there was that old sick feeling. But the Celtics' stars all made a play or two -- and collectively, that was enough, mostly because they now have so many stars. And it is time to celebrate them, because they've earned it in true Celtics fashion.

Windhorst sounds off on Luka's NBA Finals performance

Brian Windhorst sounds off on Luka Doncic's performance after the Mavericks' star player fouled out in Game 3.

Fill in the blank: Luka Doncic's Game 3 performance was ______.

Windhorst: Completely unacceptable. No one can tell Doncic anything. Not teammates, not coaches, not executives, not media, not fans, not referees. There have been a lot of pleas and promises that he'll improve, but this one is going to leave a mark. He is a truly brilliant player, once in a generation. But he is going to have to look in the mirror and confront his weaknesses before he's on the other side of a Finals. His defensive effort in these Finals has simply been crushing to his team, his complaining to the referees is painful and his frustration fouls probably just cost his team a chance at making this a series because he fouled out. He is one of the biggest stars in the league, and that means he is held to a higher standard, especially at this level. He failed to meet it in this game, and he's going to have to deal with that whether he likes it or not.

Bontemps: Not good enough. Doncic scored a lot of points, but the Celtics once again put the clamps on Doncic and Irving's teammates, forcing the duo to try to beat the best offense in NBA history by themselves. And for all of their individual brilliance, that wasn't ever going to be enough for Dallas to win. And Doncic's defense -- which was an ever-present issue during the first two games of this series -- was even worse in Game 3. Boston has the ability to put more pressure on Doncic than virtually any other team in the league by having either Brown or Jrue Holiday attack him for 94 feet defensively while any of Boston's perimeter players go at him on the other end. And as this series has gone on, it has appeared to take a toll on Doncic's energy levels, which led to some of the fouls that caused him to foul out of Game 3.

Herring: Incredible in some ways. Some of his baskets were a thing of beauty. But the nature of some of the looks he created, for himself and his teammates, still weren't good enough for chunks of the game. (This doesn't even speak to the times he failed to get back defensively after a call didn't go his way, especially during two plays to end the first quarter, which helped Boston pick up five quick points.) The third quarter, in particular, was a massive contrast in style: The Mavs took 21 shots, with 15 of them coming off the dribble, while the Celtics took 20 attempts, with just seven of those being off the dribble. The quality of the looks have consistently been the difference in this series, as Doncic and Irving are having to work too hard to simply keep it close.

What will it take for the Celtics to complete the sweep?

Bontemps: Not reverting to their bad habits, which were on display in the fourth quarter of Game 3. For most of this series, Boston has stuck with its process even when shots aren't falling and things aren't working perfectly, and it has paid off. Then came the final 10 minutes of Game 3, when the Celtics frittered away a 21-point lead. If Boston stays true to itself, it should win Game 4. If it does what it did late in this one, then the Mavericks can absolutely send this series back to Boston.

Herring: To not overthink the situation. The way they naturally play, with ball movement and solid defense -- both individually and as a unit -- is more than enough to beat this Dallas club, even when the Celtics are at less than full strength. As Tim said, they just have to stay away from the hero-ball tendencies they sometimes showcase. A championship is within their grasp, and they merely need to keep playing team basketball, which has repeatedly proved to outlast the Mavs' system that depends on one-on-one looks.

Windhorst: The Celtics started this journey when they made the Kevin Garnett-Paul Pierce trade with the Brooklyn Nets in 2013. They've methodically added players, made shrewd trades, had setbacks, dealt with playoff shortfalls, revamped their roster, managed a severe coaching change, honed their style and created a nearly perfect team for 2024. Whether the sweep happens or not, Boston has assembled a brilliant roster that has managed to peak at the right time, and it should be celebrated when the series is finished.