LAKE BUENA VISTA, Fla. (AP) — The Toronto Raptors faced a sizable early deficit. They trailed in the fourth quarter. And again in the first overtime. And again in the second overtime.

Exhausted and on the brink, the reigning NBA champions rose to the moment.

Next up: Game 7 on Friday, for a spot in the Eastern Conference finals.

OG Anunoby — the hero of Game 3 with a buzzer-beating 3 — put the Raptors ahead to stay with a 3-pointer with just under a minute left in double overtime, Kyle Lowry got an acrobatic jumper to fall with 11.7 seconds left and the Raptors beat the Boston Celtics 125-122 in Game 6 on Wednesday night.

Lowry scored 33 points in 53 minutes for Toronto. Norman Powell had 23, including a pair of free throws with 5.0 seconds remaining. Fred VanVleet scored 21 points for the Raptors, who needed the win to extend their season, and Anunoby had 13 points and 13 rebounds.

Jaylen Brown had 31 points and 16 rebounds for the Celtics, who had their starters on the floor — without a single sub — for the final 22-plus minutes, going back to 23.5 in the third quarter.

Jayson Tatum had 29 points, 14 rebounds and nine assists. Marcus Smart had 23 points, 11 rebounds and 10 assists, and missed a 3-pointer that would have tied it with about 3 seconds left in the second extra session.

Daniel Theis had 18 points for the Celtics. Theis played 47 minutes — the other four Boston starters, Tatum, Smart, Brown and Kemba Walker, all logged at least 50.