Despite a late surge from the Dallas Mavericks, the Boston Celtics were able to hold off their opponents on the road to take a commanding 3-0 series lead in the NBA Finals with a 106-99 victory.
The Celtics rode a strong third quarter into the fourth, but Dallas got out to a hot start to keep the game close as the seconds ticked down.
Mavericks star Luka Doncic fouled out with just over four minutes remaining in the game, depriving Dallas of a key shot taker.
Clutch shots down the stretch from Jayson Tatum and Jaylen Brown helped keep Boston in the lead.
Brown in particular came out strong in the second half after only grabbing six points in the first two quarters before ending the night with 30 points, eight rebounds, and eight assists.
Jayson Tatum led the Boston Celtics in scoring as they beat the Mavericks for a 3-0 series lead
After putting up only six points in the first half, Jaylen Brown (7) dropped 30 for the game
Tatum led the Celtics in points on the night with 31 alongside six rebounds and five assists.
As for Dallas, Kyrie Irving led all scorers with 35 points while the fouled-out Doncic put up a 27 point, six rebound, six assist performance.
His sixth foul came late and kept him off the floor for the final moments of the game as the referees whistled him for a blocking foul.
Boston also improved to 10-1 in these playoffs without Kristaps Porzingis after the 7-foot-2 Latvian was ruled out about two hours 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 the only other rally to match it in the NBA Finals sparked Dallas' run to its 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.
Luka Doncic reacts after fouling out in Game Three of the NBA Finals against Boston
But the absence of Doncic hurt the team late as the Mavericks only hit three of their last eight shots in the game.
Things now look bleak for the Mavericks - who now face the hill of trying to become the first team in NBA history to come back from a 3-0 deficit.
Game Four - which will either see the Mavericks extend the series or watch the Celtics win a record-setting 18th title - takes place on Friday night in Dallas.