‘The job is not done,’ focused Celtics say with Mavs on the ropes

Boston leads the series 3-0 after Wednesday’s win in Dallas.

Dallas • On the final possession of the Boston Celtics’ mighty third quarter Wednesday night, Jaylen Brown dribbled in place on the midcourt logo and waited to start his move. Sam Hauser approached with a screen to Brown’s right, but Brown crossed over between his legs to attack the other way.

Brown sped past Luka Dončić, the first level of help defense and scanned the rest of Dallas’ defense for an opening. If the Mavericks had overhelped, Brown said he would have been prepared to kick the ball out to one of his teammates on the perimeter. Instead, Josh Green stepped over to stop Brown, but not in time to cut off his path to the basket.

“They were kind of in between,” Brown said. “And when I (saw) that, it was lights out.”

Lights out on the play, which Brown finished with a high-flying dunk. Lights out, perhaps, on the NBA Finals. The Celtics opened the third quarter with a one-point deficit. They ended it with a commanding lead in Game 3, which they held on to win 106-99, and in the series, which they will have their first chance to close out Friday night.

“I’ve got to watch the film,” Jayson Tatum said, “but that was excellent basketball we played to start the third, especially on the offensive end.”

With an opportunity to step on the Mavericks, the Celtics broke out 12 minutes of their most beautiful basketball after halftime Wednesday night. They opened the third quarter with a ruthless display of execution that produced buckets on seven straight possessions. They closed the quarter by holding the Mavericks to five points over the final 5:11 while extending a six-point lead to 15. Brown’s slam, which punctuated the dominant stretch, allowed the Celtics to enter the fourth quarter with an 85-70 advantage. They still needed to escape a late Mavericks charge, but did so to move within one game of the franchise’s 18th championship.

No team so far has been able to withstand the Celtics’ best. The third quarter, during which they outscored Dallas 35-19, was a flex of how complete they are and how much smarter they have become over the years. After Brown drilled a midrange jump shot on the first possession of the quarter, pretty passing set up the next two Boston buckets. On the first, Jrue Holiday drove baseline, collapsed the defense, kicked it out to Derrick White and relocated so White could hit him back for a cutting layup. On the second, Tatum set a ball screen for White before rolling to get inside position on the defending Kyrie Irving. As soon as Daniel Gafford left the paint because he was concerned about Holiday at the 3-point arc, Brown lobbed a pass over the top of the defense to lead Tatum straight to the rim.

The Celtics were in unison, working together to solve the Mavericks defense. Coach Joe Mazzulla stressed how hard it is to recover after missing the first offensive read, but didn’t need to worry about such a problem during the third.

“That’s what we were able to do in the third quarter,” Mazzulla said. “We found the first read, bang, right there, and we got it like six, seven, eight times in a row.”

The Mavericks kept pace with the Celtics for a while, but the Boston offense didn’t slow down. Brown attacked Irving for a bucket inside, then Holiday pulled up for a 3-pointer over the top of a sagging Dončić. After Holiday picked off an errant Dallas pass, Brown drove by Dončić to the baseline, drew two other Mavericks defenders and jumped to find Tatum open near the top of the key. His 3-pointer put the Celtics ahead 64-59. On the next Boston possession, Tatum returned the favor to Brown. After spinning past Dončić, Tatum left a bounce pass for Brown to scoop up and dunk home.

The awareness. The court vision. The synergy. Everything the Celtics have focused on developing surfaced during the third quarter of Game 3. Even the first miss of the quarter, which came 4:30 into it, followed a great pass from Brown to Tatum. Moments after that, Tatum posted up hard enough to draw the attention of the entire Mavericks defense before firing a cross-court pass to White. He quickly redirected the ball to Al Horford, who immediately swung it to Brown wide open in the corner. Splash.

“I don’t know how many possessions in a row that we got a great shot,” Tatum said. “We made most of them. We might have missed a few. But the way that we started the third quarter was incredible. You know, everybody else on that court, the mindset we came out to start the third in our execution, we did a hell of a job in the start of the third quarter.”

With an injury sidelining Kristaps Porziņģis, and his status in jeopardy moving forward in the series, the Celtics entered Wednesday with pressure to take away Dallas’ hope. Boston held a 2-0 lead in the NBA Finals, but a series can change rapidly. The Mavericks could have walked away with confidence if they had won Game 3.

Even while trailing 51-50 at halftime, Holiday said he and his teammates believed they were in a good position. They had fought their way out of an early 13-point deficit. They had essentially shrugged off an aggressive start from Irving and Dončić. Onslaughts from those two can break an opponent’s defense, but the Celtics stayed committed to their game plan even after the two Mavericks stars combined for 22 first-quarter points.

“Knowing that Dallas was going to throw everything (at us), I think we withstood punches, especially earlier in the game,” Holiday said. “And we just stayed persistent. We didn’t worry about the outside stuff. We worried about the things we could control and we took care of them in the third.”

The Celtics finally had a bad possession about 5:30 into the third quarter, when Tatum took a difficult stepback jumper over the top of Dončić after a couple of actions opened up nothing. Even Tatum’s miss led to a highlight. At the other end of the court, White swatted Tim Hardaway Jr. in transition. Xavier Tillman picked up the rebound and threw an outlet pass to Holiday, who looked ahead to find Tatum for a fast-break dunk.

Minutes later, Tillman, playing because of Porziņģis’ injury, had his moment. The 26.7-percent career 3-point shooter drilled a long ball from the corner after receiving a pass from Brown. Horford said Tillman had the type of impact people remember forever.

“Obviously we’d love to have KP out there,” Brown said. “We are different when he is. But X stepped in that role, and I thought he was great. Defensively I thought he was stellar, and that big shot he made in the corner, I just knew it. I just knew when I drove, they were going to help, and he was going (to be) open. And I trusted it all the way. I just knew it was going in. I don’t know how to tell you. It was just like a divine experience. I knew X was going to make that shot, and he did. That was big for us.”

Once prone to tunnel vision while driving, Brown saw the entire chessboard. He alone accounted for 23 points during the quarter, four more than the entire Mavericks roster. He shot 6 of 9 from the field during the period and added three assists, showcasing all the work he has put in to increase his IQ and awareness.

“How can I explain Jaylen?” said Mazzulla. “The guy just has a growth mindset. He just wants to get better. He yearns to get better. He’s not afraid to face his weaknesses on the court. So when you have that type of mindset, you’re just going to be able to take on every situation that the game brings you. He puts himself in every single situation that he sees in a game. He uses six, seven, eight coaches a day, and every situation on both ends of the floor, he puts himself in that. And that’s how you have to grow, is to become vulnerable and (work) on the things that make you uncomfortable, and he does that.”

The Celtics used to play a grating style. Now, when they’re humming, no team plays more unselfishly. They had eight assists and zero turnovers in the third quarter. Maximizing the basketball math Mazzulla loves so much, they generated 11 3-point looks during the period while holding the Mavericks to two. The Celtics played as if they decided that Irving and Dončić, as great as they are, could not beat them on a diet of 2-point shots.

The Celtics still need one more win to close out Dallas, but are on the verge of their first championship since 2008. A ring would finalize what has been, statistically speaking, one of the most dominant seasons in NBA history. Boston has followed a 64-18 regular season by winning 15 of its first 17 playoff games. After posting a plus-11.7 net rating throughout the regular season, the Celtics have nearly matched that mark during the postseason. The level of competition was weak over the first three rounds, but teams rarely float through the playoffs like Boston has so far.

The third quarter illuminated several keys to the Celtics’ greatness. They have a willingness to play for one another, an ability to find answers at both ends of the court and resilience, which was necessary to stand up to a desperate opponent on the road.

“I don’t even really have words,” Brown said. “It kind of doesn’t even really feel real right now. I’m just trying to stay in the moment. It feels great to be up 3-0 in the series but the job is not done.”

This article originally appeared in The Athletic.