Al Horford made sure his former team didn’t force a Game 7. The 36-year-old Horford hit a huge 3-pointer in a late run that carried the Celtics past the Hawks 128-120 Thursday night for a 4-2 triumph in the opening-round playoff series.

After squandering a 13-point lead in the fourth quarter of Game 5, which cost them a chance to end the series in Boston, the Celtics were determined not to wilt again.

“We talked about finishing the game,” Horford said. “I felt the last game, for the most part, we were fine. But tonight there was that sense of urgency. We understood how important it was to not extend the series.”

Down by three, Boston ripped off an 11-0 run that included three straight 3-pointers, with Horford’s big shot sandwiched around 3s from Jayson Tatum and Jaylen Brown.

Murray seemed a bit out of sync, missing all five of his shots in the first half. He was better in the second half but still managed just 14 points.

The Hawks needed a few more to keep their season going.

“We were right there,” Snyder said.

Young forced the series back to Atlanta with a long 3-pointer that stunned the Celtics 119=117 in Boston, capping the Hawks’ comeback in the fourth quarter.

Coming off his 38-point, 13-assist effort, Young kept it going with 18 points in the first quarter.

But the Celtics finally clamped down on the Hawks star, whose heroics had forced Janet Jackson to postpone her scheduled Thursday concert until Friday to make room for Game 6.

Now, State Farm Arena is wide open for the summer.