The Pacers allowed 118 points to the Heat Wednesday, but played tight defense against the Celtics Friday at TD Garden to walk away with an 87-74 victory.
"We have confidence that we can beat any team in any building and this was a game that we knew to win here, we'd have to make it like an Eastern Conference playoff-type battle," Pacers coach Frank Vogel said. " And both teams defended at an extremely high level. All of our guys contributed."
The Pacers' bench outscored the Celtics' 33-14.
"There's going to be nights like that," Celtics coach Doc Rivers said. "I would say this: Brandon [Bass] was 2-for-7 and he missed five great shots. So, that's going to happen. We do have to get more out of our bench."
Allen, who returned to the starting lineup after being held out Wednesday with flu-like symptoms, led the Celtics with 23 points on 7 of 11 shooting, four of which from beyond the arc.
Six Pacers were in double figures: Darren Collison (14), Paul George (12), Danny Granger (15), Roy Hibbert (11), George Hill (13) and Tyler Hansbrough (12).
"It seemed like they played harder than us for four quarters, and that can't happen," Allen said.
2:48 4th quarter, Pacers, 77-70: Costly turnover by Pierce in the waning minutes. Allen is on tonight and Danny Granger knows it. He was waiting for that pass.
3:30 4th quarter, Pacers, 77-70: The Celtics will need a big run they've been lacking in order to extend their winning streak to five.
6:00 4th quarter, Pacers, 75-65: The Celtics are still getting crushed on the boards, 44-29, and it's reflecting on the scoreboard, too.
10:10 4th quarter, Pacers, 67-60: Allen has all five points for the Celtics in the final quarter -- a layup and a 3-pointer.
END of 3d quarter, Pacers, 63-55: Paul George helped the Pacers stay on top with four buckets, while Pierce is 3 of 15 from the floor.
3:30 3d quarter, Pacers, 53-47: Allen is perfect on three attempts from beyond the arc and leads the Celtics with 14 points. The Celtics seem to have the momentum this quarter but the Pacers aren't going away.
8:20 3d quarter, Pacers, 37-35: Allen hit a 3-pointer, Pierce took a charge, Rondo made a layup, and the Celtics are right back in it. Their offense is very explosive and tough to silence at TD Garden.
12:00 3d quarter, Pacers, 33-25: The Celtics had a huge third quarter Wednesday to pull away from the Nets. Tonight they trail by 8. We'll see in a few minutes if the Celtics try something different or stick to their system in the second half -- more likely the latter. It's worked in their previous four games.
END of 2d quarter, Pacers, 33-25: Notes: The Celtics shot 26.5 percent from the floor in the first half while the Pacers weren't much better at 33.3 percent. The Celtics are +6 with Rondo, the only Celtic in the positives. Hibbert and David West have seven rebounds apiece, and the Pacers outrebounded the Celtics 30-18.
2:24 2d quarter, Pacers, 29-25: The last time Roy Hibbert played the Celtics he scored 26 points but didn't have to face O'Neal. Tonight, Hibbert is 2-for-8 after O'Neal just stuffed him in the paint. O'Neal has three blocks and we aren't even at halftime yet.
3:28 2d quarter, Pacers, 27-25: Pacers guards aren't fooling anyone. Rondo has two steals and nearly had a third with a deflection.
5:50 2d quarter, Pacers, 25-21: Allen made a 3-pointer and has played aggressively on the offensive end. Flu? What flu?
9:36 2d quarter, Pacers, 20-14: Allen re-entered at the 11-minute mark. The Celtics need him healthy now, trailing by 6. Hansbrough made back-to-back buckets for the Pacers.
END 1st quarter, Celtics, 14-14: We're all square at the first break. Pierce is scoreless after leading the Celtics with 24 points Wednesday night and Danny Granger is 1 of 5 from the floor. The Pacers shot under 20 percent from the floor as a team, but are tied with the Celtics because of their free throw shooting: 5 of 6.
0:50 1st quarter, Celtics, 13-12: Jermaine O'Neal blocked Tyler Hansbrough's layup, then took a charge against a driving George Hill on the same possession. He's showing Doc Rivers why he belongs on the floor: Defense.
3:14 1st quarter, Celtics, 13-9: So Allen is human. He missed his first free throw attempt tonight, and has gotten off to an unusually "slow" start from the line this year (11 of 15). Allen was the first Celtics starter to exit after playing the first eight minutes.
5:27 1st quarter, Celtics, 10-9: Rajon Rondo has hit two layups and Paul Pierce has missed his first three attempts. It didn't take long for Allen to get on the scoreboard: 82 seconds.
7:45 1st quarter Some fans are booing David West whenever he touches the ball. If you didn't hear, he said earlier today that the Pacers were a better option to sign with this past offseason.
12:00 1st quarter: Ray Allen is on the floor for the first time since Monday's win against the Wizards. We'll have updates on him and the rest of the Celtics throughout the game.