OG Anunoby beat the final buzzer with a 3-pointer off an inbound pass from Kyle Lowry with 0.5 seconds remaining as the Toronto Raptors stunned the Boston Celtics 104-103 in Game 3 of their Eastern Conference semifinal series Thursday night near Orlando.

Lowry led all scorers with 31 points, Fred VanVleet added 25 and Anunoby had 12 points and 10 rebounds as the Raptors bounced back from losing the first two games of the best-of-seven series.

Game 4 will take place Saturday night.

Kemba Walker had 29 points, and Jaylen Brown scored 19 with 12 rebounds for the Celtics, who lost for the first time in seven playoff games.

Boston appeared headed to a 3-0 series lead after Daniel Theis slammed home an emphatic dunk for a 103-101 edge with a half-second to go. The Raptors called timeout, and Lowry fired the inbound over 7-foot-5 Tacko Fall to Anunoby, wide open on the far side of the court.

Anunoby connected on his shot to complete the comeback win.

Toronto was down 101-97 with 1:41 left before Lowry and VanVleet made baskets to knot the score.

The Raptors' largest lead of the fourth was 95-91 with 5:57 remaining before an 8-0 Celtics run.

Trailing by 10 to begin the second half, Toronto went ahead for the first time since the opening quarter first when Pascal Siakam hit a 3-pointer for a 68-66 lead with 3:40 left in the third. Boston equalized at 74 on a Walker trey with 1:25 to go.

A Brad Wanamaker three-point play with 5.2 ticks left survived a flagrant-foul review, and Boston entered the fourth up 80-76.

The Celtics grabbed the game's first double-digit lead, 47-37, on a Brown jumper with 4:10 to go in the half. VanVleet sank a pair of 3-pointers to get the Raptors within five, but Boston entered the break up 57-47 after Walker nailed a three with 2.7 seconds remaining.

Walker had 21 points at halftime, 17 coming in the first quarter. Brown had 10 points and 10 rebounds before the break. Lowry paced Toronto with 15 first-half points.

The Celtics led 33-28 after one quarter.

--Field Level Media