Jalen Brown scored a game-high 21 points to lead the Boston Celtics to a 114-93 wire-to-wire victory over the visiting Dallas Mavericks on Friday night.Jayson Tatum added 18 points and Marcus Smart had 17, including five 3-pointers, to pick up the scoring slack with leading scorer Kyrie Irving missing a second consecutive game with eye irritation.The Celtics also played without forward Marcus Morris, who hurt his neck after a scary fall in Wednesday’s game against Minnesota.Boston was challenged only once, when their 53-36 second-quarter lead got whittled down to 58-57 early in the third. But after Mavs rookie sensation Luka Doncic drained a 3-pointer to make it a one-point game, his 3-point attempt to grab the lead missed everything. The Celtics answered with a 21-6 run.Dallas was trying to put together back-to-back road wins for the first time this season after routing Charlotte on Wednesday. The Mavs made 10 3-pointers in the first quarter of that game.Against Boston, they made 11 for the entire game on 44 attempts. Boston finished 21 of 45 from deep.Harrison Barnes led Dallas with 20 points, while Doncic had 19 points, nine rebounds and four assists. DeAndre Jordan tallied 12 points and 15 rebounds.Dirk Nowitzki, who has averaged more points in his career against the Celtics than any other team, received a standing ovation from the Boston crowd when he checked in.But the No. 7 scorer in NBA history failed to score and missed all 10 of his shot attempts, eight from beyond the arc. In the final minutes, the Boston crowd cheered him on, trying to will him onto the scoresheet.The Celtics, who also got 16 points from Gordon Hayward, got off to a fast start, using an 8-0 run to end the first quarter with a 34-23 lead.The final six points of the spurt came on consecutive 3-pointers by reserve guard Brad Wanamaker to quickly eclipse his previous season-high of five points. He finished with eight points, four assists and three steals in a season-high 22 minutes.