Leon Powe and the Celtics outmuscled Zaza Pachulia, left, and Marvin Williams, right, and the Hawks once again last night and put Atlanta in a 2-0 hole as the first-round playoff series gets set to head down South.

The Providence Journal / Glenn Osmundson

BOSTON — If it seemed as if the Boston Celtics were trying to send a loud, painful message to the Atlanta Hawks late in last night’s NBA playoff game, you are paying attention.

With Game Two of their first round series against the Atlanta Hawks well in hand, the Celts spent much of the fourth quarter making one big play after another and then congratulating themselves for the effort. Hard fouls, rebound battles and plenty of high-fives and chest-bumps thrilled the sellout (18,624) Garden crowd and sent the Hawks slinking back home with a 96-77 loss. Boston leads the series, 2-0, with the third game set for Saturday night at Phillips Arena.

The lead intimidator was Kevin Garnett, the Celtics big man who accepted the league’s Defensive Player of the Game award before the game and left the court pounding his chest with the Celts up by 23 points and 2:25 left on the clock. Garnett finished with 19 points and 10 rebounds.

Garnett was one of five Celtics in double figures, with Ray Allen adding 15 points, Paul Pierce 14 and Rajon Rondo ringing up 12 points, 8 assists and 6 rebounds. More importantly, the team’s physical defense limited the Hawks to 38-percent shooting. Atlanta is averaging 79 points on 38-percent shooting in the series.

“It was good that we put it on them because we’ve been putting it on ourselves the first two games and in days in between at practice,” said Boston’s Allen. “If we are guilty of anything, it is probably being too overenthusiastic when we are out on the floor.”

While the Hawks didn’t admit having a problem with the Celtics twisting their noses into the ground down the stretch, they say they’ll regroup this weekend.

“That’s Coach [Doc] Rivers’ decision. Hey, Garnett does that 90 percent of the time he’s on the floor,” said Josh Childress. “The thing we have to concern ourselves with is gaining some ground at home.”

The Celtics led by four points after one quarter, 10 at the half and 18 after three. The fourth quarter only got uglier for the Hawks, and especially guard Mike Bibby. Bibby termed Celtic fans “bandwagon jumpers” on Tuesday and that slight was obviously not well received. He made just 2-of-7 shots from the floor and heard chants of “Where is Bibby?” and “Rondo’s Better!” ringing in his ears late in the game.

“It’s going to happen,” Bibby said of the game’s physical nature. “We are going to see each other a lot over the next week, so it was bound to happen. This is what everybody plays for and nobody wants to be walked over.”

Josh Smith and Marvin Williams led the Hawks with 13 points apiece.

The increased physical style began right away as the Celtics faced a little adversity when Pierce drove hard to the rim, was fouled by Joe Johnson and crumpled to the floor just 1:22 into the game. Pierce rose slowly and made one of two foul shots but he left the game a minute later and retreated to the dressing room. He didn’t return to the bench until early in the second quarter and managed eight points in 11 first-half minutes. He was treated for a sore back after the game.

After trailing, 7-5, the Celtics got their offense in gear and exploded for a 13-2 tear and 20-9 lead. Rondo and Garnett led the way with the point guard dishing for five assists in the first quarter alone and Garnett controlling the offensive attack out of the post. The Celts let down their guard a bit at the end of the quarter as the Hawks scored 9 of the final 11 points to cut their deficit to 24-20.

But it didn’t take the Celtics long to regain control, this time thanks to its bench. Sam Cassell supplied the spark with eight points in the opening 2:52 to stake Boston to a 34-24 lead. The Celts added an 11-2 run later in the quarter for a 46-31 lead before Atlanta scored the final five points of the half to make things interesting (52-42) at the break.

That feeling didn’t last long. Pierce hit a 3-pointer to open the second half scoring and start an 11-4 spurt for a 63-46 lead. The Celtics kept on rolling through the remainder of the quarter and held a commanding 76-58 lead after three. The Celts played with a 20-point lead most of the fourth quarter and both teams were squawking at each other after several hard fouls.

kmcnamar@projo.com