Paul George scored 16 points for the Pacers, who had all five starters in double figures. David West added 11 points and 16 rebounds, and George Hill finished with 14 points.
Center Roy Hibbert had his 14th double-double of the season with 12 points and 12 rebounds. Lance Stephenson returned to the starting lineup with Danny Granger back down with a sore knee and chipped in 12 points.
The Celtics' final two baskets both came off busted defensive assignments. Avery Bradley was left all alone under the basket to tie the game at 81 off an assist from Garnett. The same happened on Green's layup.
"We just didn't talk and didn't communicate," George said about the final play.
Granger could miss another week with the knee issue. He missed the first 54 games with the same injury and sat out the second half of Sunday's victory over Chicago after aggravating it.
In other games *
At Miami, LeBron James scored 26 points, including a go-ahead layup with 3.2 seconds left, and the Heat scrambled late to beat the Orlando Magic, 97-96, and extend its franchise-record winning streak to 16 games.
The Heat blew a 20-point, second-half lead and then rallied from a five-point deficit in the final minutes. Orlando's Nic Vucevic had 25 points and 21 rebounds.
* At New Orleans, Kobe Bryant scored 13 of his 42 points during a 20-0 run in the last 6:22 of the fourth quarter, and the Los Angeles Lakers overcame a 25-point deficit to fend off the Hornets, 108-102.
* At Cleveland, Kyrie Irving scored 20 points and made all the big plays down the stretch, rallying the Cavaliers to a 104-101 victory over the Utah Jazz.
* At Charlotte, Deron Williams had 20 points and eight assists, Joe Johnson added 22 points, and Brooklyn overcame a 10-point halftime deficit to beat the Bobcats, 99-78. Reggie Evans grabbed 16 rebounds and Brook Lopez had 16 points and five rebounds for the Nets.
* At Auburn Hills, Mich., Raymond Felton scored 26 points, and the New York Knicks pulled away in the fourth quarter to beat the Detroit Pistons, 87-77, despite Carmelo Anthony's absence. Anthony sat out after injuring his right knee Monday.
* At Minneapolis, Ricky Rubio had 15 points, 11 assists, seven rebounds and six steals to lead Minnesota to an 87-82 victory over Washington.
* At Memphis, Marc Gasol had 23 points and 12 rebounds, Jerryd Bayless scored all 13 of his points in the final 13 minutes, and the Grizzlies beat the Portland Trail Blazers, 91-85.
* At Dallas, Dirk Nowitzki scored 22 points, O.J. Mayo had two big fourth-quarter baskets and a career-high 12 assists, and the Mavericks bounced back from a blowout loss in Houston with a 112-108 victory over the Rockets.
* At Phoenix, DeMar DeRozan scored 15 points and Amir Johnson added 14 to lead Toronto to a 98-71 victory over the Suns.
* At San Antonio, Tim Duncan had 18 points, 10 rebounds and five blocks to lead the Spurs to a 101-83 win over Chicago.