LOS ANGELES — The Boston Celtics, fueled by their star duo of Jayson Tatum and Jaylen Brown, held off a furious Dallas rally to beat the Mavericks 106-99 on Wednesday and take a 3-0 stranglehold on the NBA finals.

Tatum broke out of his scoring doldrums to score 31 points. Brown scored 15 of his 30 in a scorching third quarter and the Celtics held on to move within one victory of a record-setting 18th NBA crown.

Boston, who currently share the record of 17 titles with the Los Angeles Lakers, can close out the series in Game 4 in Dallas on Friday.

"We are not relaxing or anything like that," Tatum said, "not even focusing on winning on Friday or whatever.

"However long it takes, that's our motto."

The Mavericks go into Friday knowing full well that no team has rallied from 3-0 down to win an NBA playoff series.

With their backs against the wall, the Mavericks sliced a 21-point fourth-quarter deficit to one on Kyrie Irving's jump shot with 3:37 remaining.

By that point, Mavs star Luka Doncic could only watch in frustration. He fouled out with 4:12 remaining, earning his fifth and sixth fouls in less than a minute.

Mavericks coach Jason Kidd challenged both and lost, Doncic departing with the Mavs down by three after he was whistled for a blocking foul on Jrue Holiday.

Dallas kept pressing, but the Celtics had the answers. Irving found Dereck Lively for a cutting dunk that pulled the Mavs within 100-98 with 1:20 remaining.

But Brown drilled a jump shot and after Irving missed a tough three-pointer Derrick White and Tatum each made a pair of free throws and the Celtics notched their 10th straight playoff victory, remaining unbeaten on the road this postseason.

"That was a big-time win for us, and I'm proud of how we played today, Brown said. "They had some momentum, but we kept our poise. We made timely baskets.

"We got some good shots going in, and we found a way to win."

Irving shook off subpar shooting performances in the first two games to lead the Mavericks with 35 points. Doncic finished with 27 points, six rebounds and six assists before fouling out for just the third time in his career.

Doncic was clearly frustrated with the officiating.

"We couldn't play physical," he said. "I don't want to say nothing... you know, six fouls in the NBA Finals — c'mon man. (Do) better than that."