Instant analysis: How the Hawks rebounded to turn back the Celtics in Game 3

Jayson Tatum (29 points, 10 rebounds) and the Celtics ran into a Hawks team that defended its home court in Game 3.Jim Davis/Globe Staff

ATLANTA — After two blowout wins over the Hawks in Boston, it appeared the Celtics were on an inexorable march to the second round. But they hit a pothole in Atlanta on Friday night, as the Hawks punished the Celtics’ elite defense en route to a 130-122 win that pulled them within 2-1 in the Eastern Conference series.

Trae Young had 32 points and 9 assists to lead the Hawks, who shot 56 percent from the field. Jayson Tatum finished with 29 points and 10 rebounds to lead Boston. The Celtics made 43.8 percent of their 3-pointers and had been 26-0 this season when shooting 43.2 percent or better.

Young spent much of the fourth quarter finding success attacking switches against Celtics big man Al Horford. He had three runners and an assist early in the period, and with 2:22 left shook Horford for a step-back 3-pointer that gave Atlanta a 121-116.

But the Celtics lingered with a pair of Marcus Smart baskets before Tatum had an open 3-pointer from the right arc that would have tied the score with a minute left. But the shot missed, and Young converted another runner at the other end that made it 126-121 with 45.4 seconds left. Jaylen Brown missed a 3-pointer after a timeout, and two Young free throws clinched the win.

Observations from the game:

⋅ The Celtics defense went up a level at the start of the fourth. They forced five turnovers over the first 3:22. Derrick White drew a charge to break up a three-on-one break, and Smart slid across the floor for a steal. This intensity was needed earlier, however.

⋅ Atlanta made a minor defensive tweak at the start, shifting center Clint Capela onto Smart. The Hawks were pulverized on drives in the first two games of this series and this looked like an attempt to shift that. Smart willingly pulled Capela from the hoop and fired away from long-range.

⋅ Tatum started the game by missing a wide-open 3-pointer from the right arc. For Atlanta, the result was fine, but the situation was concerning. Tatum faced little resistance in his next two attempts, and hit them both. That gave him the rhythm and confidence to connect on his next try, a deep, off-the-dribble attempt from the top of the key.

⋅ The Hawks took more 3-pointers than the Celtics in Game 2, a surprising result given their differing shot profiles during the regular season. But the Celtics seemed determined to flip that around in the opening quarter of Game 3, when they were 9 for 16 from beyond the arc while Atlanta was just 2 for 7. The Hawks were probably encouraged to be down by just 4 despite Boston’s long-range onslaught.

⋅ The Celtics led by as many as 9 points in the first quarter and appeared destined to cruise to another lopsided win. But the Hawks’ offense was absolutely scorching during the second quarter, with most of the boost coming from its bench. The Celtics were a bit late on rotations and Atlanta punished a generally potent defense by going 17 for 23 from the field. In the first half, the Hawks bench was 13 for 14 shooting overall, led by Bogdan Bogdanovic, who was 6 for 6.

It was definitely not playoff-level defensive intensity by the Celtics, who looked like a team that remembered how easily the first two games had gone.

⋅ Celtics coach Joe Mazzulla stuck with an eight-man rotation during meaningful minutes over the first two games of this series, but went nine-deep in the opening quarter Friday, with Grant Williams getting his first look of the series. He had a pair of productive first-half stints in which he got back to doing what he does best. He hit a pair of 3-pointers, took a charge, had a steal, and grabbed an offensive rebound that led to free throws.

Williams checked back in late in the third quarter and hit his fourth 3-pointer in as many tries just before the buzzer, pulling Boston within 100-93 at the start of the fourth. The Celtics will need Williams in a semifinal series against the 76ers, so there’s value in these opportunities to contribute.

⋅ The third quarter started with great promise for the Celtics. They forced three turnovers in the first 2 minutes, 20 seconds, and began to find those easy opportunities at the rim that were present in the first two games. But after an 8-0 Boston run tied the score, the Hawks called timeout and went on an 8-0 burst of their own. Atlanta had answers for most of the night.

⋅ No NBA fan base has ever really had anything against Malcolm Brogdon. He generally just goes about his business. But on Friday morning, the Atlanta native took a mild shot at the Hawks fan base that tends to be somewhat indifferent.

“I mean, historically, these fans haven’t been the most dedicated,” he said. “And that’s myself included, coming up. I was always an NBA fan, but not Hawks specifically.”

Those words spread, and Brogdon was booed whenever he touched the ball.

More Celtics-Hawks coverage

Shaughnessy: Celtics in Game 3, and they deserved to lose

Washburn: Celtics came to play in Game 3, they just didn’t come to rebound

Story of the game: Joe Mazzulla expected ‘a big punch’ from Hawks, and that’s exactly what Celtics were hit with

Box score: Hawks 130, Celtics 122