Jayson Tatum and Jaylen Brown embraced tightly following their pivotal roles in Boston's narrow escape, preventing the largest collapse in an NBA Finals game since at least 1997.

Their reward? These Celtics stars are now on the cusp of joining the ranks of illustrious predecessors by adding another championship banner to hang above the famed parquet floor.

Tatum scored 31 points, with Brown adding 30, as the Celtics withstood a fierce comeback from Dallas to move closer to a historic 18th title with a 106-99 victory over the Mavericks on Wednesday. This victory gives them a commanding 3-0 series lead.

Brown also contributed eight rebounds and eight assists, further solidifying Boston's dominance with a franchise-best 10th consecutive playoff win and maintaining a flawless 7-0 record on the road this postseason. A victory in Dallas on Friday would clinch the series and break their tie with the Lakers for the most NBA championships.

Boston can now dismiss the near-collapse, having led by 21 points with 11 minutes remaining.

"Not really trying to look too much into it," Tatum said. "The game of basketball is about runs. It’s never going to go like you expected. If you want to be a champion, you have to be resilient in those situations, and we did that tonight."

Boston also improved to 10-1 in these playoffs without Kristaps Porzingis after the 7-foot-2 Latvian was ruled out before the game because of a rare tendon injury in his lower left leg sustained in Game 2.

The status of Porzingis for the rest of the series appears in doubt, but it might not matter. None of the previous 156 teams to face a 3-0 deficit has rallied to win an NBA playoff series.

The Mavs almost pulled off a crazy comeback to avoid the big hole –13 years after Dallas had the biggest fourth quarter rally in the play-by-play era of the NBA Finals (since 1997) when a 15-point comeback in Game 2 started its run to the franchise’s only title against Miami.

Boston led 91-70 at the end of a 20-5 run early in the fourth quarter before Dallas answered with a 22-2 spurt to get within a point with 3 1/2 minutes remaining.

The problem was Luka Doncic picking up his sixth foul with 4:12 remaining when a challenge was unsuccessful before Kyrie Irving, who scored 35 points, hit a jumper to get Dallas within one.

Tatum and Brown saved the Celtics from there, with some help from Derrick White, who scored 16. Those three combined for the remaining 13 Boston points to get the Celtics within a victory of their first title since 2008, and just the second since 1986.

The Celtics have led 3-0 in the NBA Finals only once, finishing off the Lakers in a sweep in 1959.

The first step for Dallas is trying to avoid getting swept in a seven-game series for just the second time in franchise history.

"We just got to make history," rookie Mavs center Dereck Lively II said. "We got to go out there and we just got to play like our lives are on the line."

In a game that seemed over early in the fourth, the score was stuck on 93-90 for more than three minutes. That included when Doncic was called for a blocking foul on a driving Brown.

The Mavs had nothing to lose with the challenge, since it meant trying to save their superstar from disqualification.

Without Doncic, P.J. Washington Jr., Irving and Tim Hardaway Jr. each missed a 3-pointer in the final minute as Irving's personal losing streak against his former team reached 13 games.

"We had a good chance," Doncic said. "We were close. Just didn’t get it. I wish I was out there."

An energized Dallas crowd was ready for its first finals game in 13 years, with Super Bowl-winning quarterback and Mavs fan Patrick Mahomes of the Kansas City Chiefs frequently getting out of his seat near midcourt.

The Mavs used the needed boost coming off two losses in Boston, taking their biggest lead of the series while running out to a 22-9 lead. Doncic and Irving drove for buckets while also hitting a 3 apiece.

The Celtics answered with a 21-9 finish to the first quarter. Sam Hauser hit two of his first-half 3s – on three attempts—to help wrap up a run that started with four points from Brown and a 3 from Tatum.

Defense dominated the start of the second quarter, Boston holding a 5-2 edge nearly six minutes in before Irving and Tatum traded 3s to start a scoring burst.

"They came out swinging," Tatum said. "That was to be expected. They were at home, the crowd was behind them. We expected their first punch."

Once they withstood it, it appeared the Celtics would coast after outscoring the Mavs 35-19 in the third quarter, before the Mavs' late rally. And the answer from Tatum and Brown.

"We’ve been in those moments a lot," Brown said. "And we’ve been in those positions, and we’ve lost. It was great to overcome that with my brother, Jayson, and with our team. That was special."

After it was over, pockets of Celtics fans screamed with delight in a mostly empty arena, seemingly starting the celebration of the inevitable.

To everyone but the Celtics.

"You’ve got to understand we are just as vulnerable if not more vulnerable than they are," coach Joe Mazzulla said. "When you understand that you’re vulnerable and your back’s against the wall, you’ve got to fight. And so that’s the mindset that we have to have."