Volkswacht Bodensee - Celtics overpower Mavericks 107-89 in game one of NBA Finals

Porzingis missed 10 games after straining his right calf in the first round of the playoffs but made an immediate impact on his return in front of a raucous home crowd.

The Celtics built a 29-point lead in the first half and then thwarted the Mavericks' third-quarter surge to gain the upper hand in the best-of-seven championship series.

Porzingis came off the bench against his former team and scored 11 points with three rebounds and a pair of big blocks in the first quarter as Boston jumped to a 37-20 lead.

After eight lead changes in little more than six minutes, the Celtics began to impose themselves, pulling away with the help of seven three-pointers in the first quarter alone and keeping up the relentless pace as the Mavs struggled to get their offense firing.

Boston finished with 16 three-pointers on a whopping 42 attempts. Jaylen Brown scored 22 points to lead six Celtics players who scored in double figures.

Brown had three of the Celtics' nine blocked shots and three of their six steals in an outstanding defensive display. Porzingis finished with 20 points and Jayson Tatum scored 16 points with 11 rebounds and five assists.

- Doncic scores 30 -

Dallas star Luka Doncic scored 30 points and grabbed 10 rebounds. But he had just one assist and star teammate Kyrie Irving was limited to 12 points on six-of-19 shooting.

Nevertheless, the Mavs managed to slice the deficit to eight points in the third quarter, only for the Celtics to pull away again.

"Defensively we made some big-time plays," Brown said. "When they cut it to eight, that's when the game started.

"I liked how our team responded. We stayed composed. Offensively, we got to our spacing and was able to push that lead back out and make some plays on offense.

"That was a big third quarter," he said.

Doncic, who has been playing through a right knee injury and a sore left ankle, struggled to find his shot.

He picked up the pace in the second quarter but Dallas couldn't find a way to slow the Celtics, who pushed their lead to 29 points, 58-29, on Tatum's three-pointer with 4:11 left in the first half.

That capped a 14-4 scoring run that included a steal and driving dunk from Brown.

The Celtics' early surge had TD Garden rocking, the crowd featuring luminaries from around the sports world including Manchester City manager Pep Guardiola.

Dallas made a push to start the third, when the Celtics went cold from three-point range and Dallas heated up.

Doncic drilled a trey to cut the deficit to 72-64 with 4:28 left in the period.

"I think in those moments we were playing our basketball," Doncic said. "We were getting stops. We didn't allow them to offensive rebound. We were having fun out there those couple moments, and that's what we've got to do more."

It didn't last however. A cutting dunk from Porzingis keyed a 14-0 scoring run that included Brown's rejection at the rim of Derrick Jones Jr. and another Brown block on Irving.

Three-pointers from Tatum, Al Horford and Brown saw the Celtics take an 86-66 lead into the fourth.

"When a team goes on a run, you've got to manage it, you've got to stay composed, and you've got to keep playing basketball," Brown said.

"It's almost like you just have short-term memory a little bit, like the team's not even on a run."

Boston will try to double their advantage when they host game two on Sunday.

"First to four, we've got to focus on the next game," Doncic said, adding that the key to turning things around on Sunday will be to "take those threes away."

"That's what hurt us the most," he said.

J.Sauter--VB