A poor third quarter did the Indiana Pacers in during Game 1 of their first-round series with the Boston Celtics.

In Game 2, Boston seized on a fourth-quarter collapse by Indiana.

Kyrie Irving scored 37 points and Boston rallied late in the fourth quarter to beat Indiana 99-91 Wednesday night and take a 2-0 lead in the best-of-seven series.

Coming out of a timeout and with a chance for Indiana to tie, the Pacers' Wesley Matthews threw an inbounds pass into the bench on the other side of the court with 12.1 seconds left. On the ensuing play, the Celtics' Al Horford passed to Jayson Tatum, who was fouled on a two-handed dunk. He completed the three-point play to make it 97-91 with 8.8 seconds left.

The Pacers turned it over again and the Celtics were able to close out the game at the free throw line.

Tatum scored 26 points, including his thunderous dunk down the stretch to help punctuate a 10-0 run by Boston over the final five minutes.

Irving said being able to have this kind of performance at TD Garden after sitting out the playoffs last season wasn't lost on him.

"It's just been a long journey," Irving said. "From having those two knee surgeries and watching the team last year and finally getting chance to lace them up for the Boston Celtics in the NBA playoffs — it's nothing like it."

After scoring only eight points in the third quarter of Game 1, the Pacers scored only 12 points in the fourth of Game 2.

"It's always been one quarter that kills us in the second half," Thaddeus Young said. "We're getting good looks and shots are not falling. ... We gotta put together a 48-minute game and we haven't been able to that."

Bojan Bogdanovic led Indiana with 23 points. Young added 15 points. Myles Turner finished with six blocks.

Game 3 is Friday in Indiana.

Darren Collison scored seven points during a 10-0 run that gave the Pacers a 70-58 lead in the third quarter as turnovers began to pile up for the Celtics.

Indiana led 79-68 entering the fourth. Horford opened the final period scoring on a hook shot in the lane and Tyreke Evans responded with a 3-pointer on Indiana's first possession.

But then Boston got hot, using a 16-0 run, including eight straight by Irving, to take an 86-82 lead with 5:04 to play. Indiana missed 10 straight shots during the run, finally breaking a nearly eight-minute scoring drought with a 3-pointer by Matthews in front of the Celtics' bench.

Bogdanovic hit a 3-pointer from virtually the same spot as Matthews to put the Pacers back in front. Gordon Hayward responded with a jumper, before Bogdanovic hit another 3 over Horford that made it 91-89 Pacers with 2:16 remaining.

Following an Indiana miss, Tatum connected on a 3-pointer from the corner. And after Horford blocked Bogdanovic at the rim, Tatum found a cutting Hayward for a layup and the Pacers were undone by their late turnovers.

"Missed a couple of good looks. Held them under a 100. The defense was still there. They made more timely baskets than we did," Matthews said.

Horford was a game-time decision with an illness but was able to remain in the Celtics' starting lineup. He was noticeably a step slower at the outset and didn't' take his first shot until late in the second quarter. He didn't score his first points until the fourth, finishing with four points, 10 rebounds and four assists for the game.

"It wasn't just about putting points on the board, it was just about doing the little things," Irving said. "It was a gritty win."

TIP-INS

Pacers: Were outrebounded for the second straight game 41-32.

Celtics: Coach Brad Stevens received a technical foul in the third quarter. It marked just was just third of the season.

BETTER START

After both teams struggled from the field in Game 1, they combined to hit 10 straight shots to open Game 2.

The Pacers shot 65 percent in the first quarter, but were just 7 for 20 from the field and 0 for 7 from beyond the 3-point arc in the second. The Celtics seized on it, outscoring them 23-17 in the quarter and taking a 52-50 halftime lead.

PATRIOT SUPPORT

Several New England Patriots were in attendance for Game 2. Among those in attendance were coach Bill Belichick, reigning Super Bowl MVP Julian Edelman, Devin and Jason McCourty, Sony Michel and Duron Harmon.

UP NEXT

The series shifts to Indianapolis for Game 3 on Friday.