Kristaps Porzingis returned from a 10-game absence to record 20 points off the bench and the Boston Celtics snuffed a second-half rally to beat the Dallas Mavericks 107-89 on Thursday night in Game 1 of the NBA Finals.

Porzingis hadn't played since Game 4 of Boston's first-round series against the Miami Heat due to a right calf strain. He seemed unfazed by the long layoff, though, shooting 8-for-13 from the field while collecting six rebounds and three blocks.

After trailing by as many as 29 late in the first half, Dallas got back into the game thanks to a third-quarter outburst headlined by Luka Doncic.

The star guard accounted for 10 points during the Mavericks' 22-9 surge to open the frame, with his 3-pointer cutting Dallas' deficit to 72-64 with 4:28 to go.

The Celtics responded emphatically, rattling off the next 14 points to take a 22-point lead.

Daniel Gafford closed the third with a pair of free throws to get Dallas within 20, but the Mavericks trailed by at least 17 for the entirety of the fourth.

Game 2 is set for Sunday in Boston.

Jaylen Brown led the Celtics with 22 points and added six boards, three steals and three blocks. Jayson Tatum chipped in 16 points and 11 rebounds, while Derrick White netted 15 points.

Doncic recorded 30 points and 10 rebounds for Dallas, which got outshot 47.6 percent to 41.7 percent overall. P.J. Washington went for 14 points, Jaden Hardy scored 13, and Kyrie Irving, showered with boos all night, had 12.

Although Porzingis didn't draw the start, he wasted no time setting the tone after checking in with 7:17 left in the first quarter.

The big man tortured his former team, scoring 11 points and blocking a pair of shots in the period to lift the Celtics to a 37-20 advantage after 12 minutes of action. No team has ever built a larger lead in the first quarter of Game 1 in Finals history.

Boston kept pouring it on, using a 14-2 run to go up 58-29 with 4:11 remaining in the second quarter. However, Doncic proceeded to erupt for nine points over the final four minutes of the first half, helping the Mavericks pull within 63-42 by the break. (Reuters)