Luka Doncic nailed a game-winning, step-back three-pointer with one-tenth of a second left as the Dallas Mavericks earned a 110-107 home win over the Boston Celtics on Tuesday at American Airlines Center.

Doncic and Celtics guard Jaylen Brown dueled down the stretch.

Brown hit a 13-foot jumper with 37.6 seconds left to put Boston up 105-104.

In response, Doncic hit a three-pointer with time running out on the shot clock to put Dallas back up two.

Brown then made a game-tying layup with under 10 seconds left, but Doncic called game with his three-point dagger.

Boston had no time to get off a shot in response, and the game was over.

Dallas had led 101-89 with 3:57 left, but the Celtics rolled off a 16-3 run in response capped by Brown's jumper. Kemba Walker scored nine of Boston's points in that span.

The Mavs were without big man Kristaps Porzingis, who missed his second straight game because of lower back tightness.

The 15-15 Mavs have won six of their last seven games. The 15-16 Celtics have lost five of their last seven.

Notable Performances

Celtics SG Jaylen Brown: 29 points, 7 rebounds, 5 assists

Celtics F Jayson Tatum: 28 points, 6 rebounds, 4 assists

Celtics PG Kemba Walker: 21 points, 4 rebounds, 3 assists

Mavericks PG Luka Doncic: 31 points, 10 rebounds, 8 assists

Mavericks G Jalen Brunson: 22 points, 2 rebounds, 2 assists

Mavericks C Boban Marjanovic: 10 points, 8 rebounds, 1 assist

Doncic, Brunson, Marjanovic Deliver for Mavs

The Mavs were 9-14 earlier this month after a six-game losing streak, but the arrow on their season is pointing up now that they're back to .500 thanks to their huge win over the Celtics despite missing Porzingis.

Doncic was the hero in this one, but a pair of reserves in Jalen Brunson and Boban Marjanovic helped pave the way to the win.

Doncic and Brunson nearly scored half of the Mavericks' 110-point total by themselves, combining for 53 points thanks in part to hitting 11-of-15 three-pointers.

The Mavs largely struggled from the field outside Doncic, Brunson and Marjanovic (10 points on 5-of-7 shooting, plus-13 rating). Dallas needed its superstar and top bench player to come through, and the Mavs were able to hold off a late and furious Boston rally.

Doncic drew in the defense and dished to Marjanovic down low for an early bucket during a frenetic first quarter that featured 65 total points:

The Luka-Boban connection continued in the second half:

The fourth quarter was all Brunson, who scored 16 of Dallas' 30 points in the final 12 minutes. A James Johnson steal led to a basket in transition from Brunson, who executed the tough finish:

He also nailed a big three-pointer over Walker to put Dallas up 12:

The shot seemed to signal the beginning of a relatively stress-free ending to the game. Although that didn't happen, the Mavs were able to rely on Doncic down the stretch for the victory.

Celtics' Tough Season Continues

A few different NBA teams can make cases for having the most excruciating and painful losses this season.

The Phoenix Suns are 0-3 in overtime games and blew a 24-point lead to the Brooklyn Nets in regulation. The Miami Heat are also 0-for-3 in overtime and fell to the Milwaukee Bucks by 47. And the 7-25 Minnesota Timberwolves are 1-5 in games decided by three points or less.

However, none of them may hold a candle to the Celtics, who are stacking up tough defeats at this point. 

Two nights earlier, Boston led the New Orleans Pelicans by 24 points only to fall in overtime after Jayson Tatum needed a clutch bucket with two-tenths of a second left just to get them there.

Earlier this month, the below-.500 Atlanta Hawks dropped 122 on them in Boston while shooting 57.1 percent from the field. The Celtics also endured back-to-back losses to the Washington Wizards and Detroit Pistons, who were the bottom two teams in the East at the time.

They also traded blows with the Los Angeles Lakers at the end of January, but they lost 96-95 after Walker's shot and Daniel Theis' buzzer-beating follow-up didn't fall. In addition, Marcus Smart suffered a Grade 1 left calf strain that night and has been out for over three weeks.

Dallas only added to the pain of a bewildering season Tuesday.

The matchup looked all but lost down the stretch following Brunson's three, but the Celtics fought hard on their 16-3 run in response.

It was the Tatum and Walker show to start. The two combined for the run's first 14 points, with Walker leading with nine.

During that stretch, Tatum did a fantastic job to navigate three defenders and find a wide-open Walker, who nailed a huge three:

Then it was Brown's turn, as he hit a big shot over center Willie Cauley-Stein to put Boston up one:

That led to Doncic's three, which led to Brown's layup, which led to Doncic's back-breaking shot to give Boston another excruciating loss. 

In the end, the C's fought hard all night, especially in the end. They stayed within striking distance despite getting only 29 points outside the Walker-Tatum-Brown trio and nearly erased a 12-point deficit only to lose after back-to-back threes from Doncic.

Unfortunately, moral victories aren't helpful for the C's, who now find themselves under .500 and searching for answers. The good news is that the regular season isn't even half over, and it's possible those tough losses become hard-earned wins in the second half of the year.

What's Next?

Boston will visit the Atlanta Hawks at State Farm Arena on Wednesday at 7:30 p.m. ET. Dallas will hit the road to play the Philadelphia 76ers at Wells Fargo Center on Thursday at 7 p.m.