Third quarter explosion ousts Orlando

When the quarter came to a merciful end, the Celtics had stretched their lead to 21 points. Orlando could never recover, and Boston eventually rolled to a 120-89 win to win the series, 4-1.

Boston will face the winner of the first-round series between the Knicks and Pistons, which New York leads, 3-2, after losing Game 5 on Tuesday.

Jayson Tatum had 35 points, 10 assists, and 8 rebounds to lead the Celtics. Jaylen Brown added 23 points and 6 rebounds, and his biggest moments came when he drew both Banchero’s fourth and fifth fouls.

The Celtics were 0 for 6 from the 3-point line in the first half, but 13 for 18 in the second. Franz Wagner had 25 points for the Magic and Banchero finished with 19, but his lengthy third-quarter absence was simply too much to overcome.

Observations from the game:

▪ In Game 3, Banchero collected his third foul early in the second quarter and stayed in the game. In that situation, he mostly let Boston’s ball-handlers drive past him, but he never picked up his fourth.

Tuesday, the results were even worse. This Orlando team is extremely challenged on offense, and without Banchero, it had no real chance. To add insult to injury, the Magic challenged the foul on the Brown basket and lost. It seemed to be a clear infraction, and their urgency spoke to the magnitude of the moment.

Orlando actually held up for about four minutes without Banchero, but the dam eventually broke. While Mosley’s initial decision was logical, it was surprising that he did not go back to Banchero as things truly collapsed. At that point, there was no use saving him.

▪ Tatum was primarily involved as a distributor at the start. He dished out five early assists and missed his first two shots, including a fairly simple layup. But his points can arrive in bunches, as evidenced by him pouring in 8 points over the final 2:15 of the opening quarter.

▪ Orlando has done an excellent job of limiting the Celtics’ 3-point attempts in this series. Entering Game 5, the Magic had held Boston to 33 3-point attempts per game, 15 below its season average.

The first half on Tuesday was the most severe of all, however. The Celtics fired up just six tries and missed all of them. Coach Joe Mazzulla has stressed that Boston never really hunts 3-pointers, it just takes the best shot available. And Boston did find plenty of success closer to the rim. It made 20 of 32 two-pointers in the first half, and held a 32-16 edge in points in the paint.

▪ Along those lines, the Celtics had to be encouraged by the fact that they trailed just 49-47 at the break despite missing all six of their 3-pointers and committing nine turnovers. Of course, Orlando was just 4 for 18 from beyond the arc. And in the second half, Boston got back to doing what it does best.

▪ The Magic had a brutal two-for-one awareness at the end of the second quarter. Banchero grabbed a rebound off a Brown miss with 52 seconds left, and Orlando could all but have ensured that the Celtics got just one more shot in the half. Instead, Banchero pulled up for a 3-pointer with 46.5 seconds to play. The shot missed and Wendell Carter Jr. secured the rebound before he was fouled, at least saving Orlando from a total mess.

But he made just one of two free throws, and Tatum rushed upcourt for a layup with 30 seconds left to lock in the two-for-one. The Magic committed a shot-clock violation, and Tatum faced little resistance as he went the length of a court for a dunk in the final second to make it a two-point game at the half.

▪ Was the 8:30 p.m. scheduled tip not late enough for you? Well, the start was pushed back to 8:51 because the Pacers’ Game 5 win over the Bucks went to overtime.

Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him @adamhimmelsbach.