Jeff Green laid in the game-winning basket with a half-second remaining as the Boston Celtics stole an 83-81 decision over the Indiana Pacers at Bankers Life Fieldhouse.
The Celtics trailed by nine with 4 1/2 minutes left in regulation and scored the final 11 points to capture their fourth straight victory.
Kevin Garnett finished with 18 points and 10 rebounds and assisted on the deciding bucket, while Paul Pierce and Avery Bradley chipped in 13 points apiece for the victors.
"We started to adjust and impose our will a little more," Garnett said. "We made shots and executed plays when we had to."
All five Pacers starters scored in double digits, but Indiana was held to 13 points in the fourth quarter. Paul George had a team-high 16 points, and David West totaled 11 points and 16 rebounds in the loss, the club's second in its last nine games.
If the playoffs had started before the game, these teams would have squared off in the first round with the Pacers as the No. 2 seed and the Celtics coming in at No. 7 in the Eastern Conference.
Indiana played like the favorite for 44 minutes, as it held an 81-72 lead after George drained a 3-pointer with 4:36 remaining.
That's when the Pacers went cold, missing their last seven shots as Boston began its comeback. Jason Terry hit a floater before George goaltended a Bradley layup. Pierce added a 3-pointer, cutting the deficit to 81-79, and Bradley scored inside to tie things with 1:21 on the clock.
After trading misses, Roy Hibbert was forced to take an 18-footer with the shot clock winding down, and his attempt rimmed out. Boston was essentially able to hold for the last shot and drew up a play that began with Garnett controlling the ball at the top of the key.
Pierce set a key pick on West at the elbow to free up Green, who leaked behind the defense and momentarily bobbled Garnett's feed before recovering in time to put in the game-winner.
"We had some defensive breakdowns down the stretch," Pacers head coach Frank Vogel said. "Give credit to Boston...especially in the fourth quarter."
With only time for a tip-in, the Pacers called timeout and threw a lob to George under the basket. Pierce played perfect defense to deny the All-Star forward at the rim, and the Celtics escaped victorious.
The Pacers scored the last seven points of the first quarter and never trailed until the final second. They led, 27-19, heading into the second and 49-42 at halftime.
Their biggest lead came midway through the third when Lance Stephenson's dunk capped a 10-2 run for a 63-49 cushion.
Boston trailed, 68-58, before opening the fourth quarter on an 11-2 flurry. George Hill ended Indiana's nearly six-minute field goal drought with a 3- pointer, then added another deep make and a dunk on the next two possessions to start what appeared to be a game-sealing 8-0 run.
The Celtics have won nine of the last 12 meetings, including four in a row ... With his sixth rebound, Garnett passed Wes Unseld for 10th on the NBA's all- time list. He now has 13,774 rebounds for his career ... Hibbert logged 12 points with as many rebounds, while Hill and Stephenson netted 14 and 12 points, respectively ... Green scored 11 points ... Indiana fell to 25-7 at home.