ATLANTA — Paul Pierce knocked down the free throws to clinch it, then dropped to a knee near midcourt.

He wasn’t planning on Tebowing, but it just felt right.

With a stunning performance, Pierce single-handedly led the Boston Celtics to a playoff win – even without their floor leader.

Pierce battled through another tough shooting night to score 36 points, and the Celtics wiped out Atlanta’s 11-point lead in the second half, stunning the Hawks 87-80 on Tuesday in Game 2 of the Eastern Conference series.

Boston heads home for Game 3 on Friday night tied 1-1. Rajon Rondo will be back for the Celtics in that one, his shorthanded team having claimed the home-court edge even while he served a one-game suspension for bumping a ref in the postseason opener.

Pierce made sure Rondo wasn’t missed, outscoring the Hawks all by himself over the last 15:08.

“I have a lot of experience, a lot of confidence from being in those moments,” Pierce said. “You believe in yourself, your coach believes in you, your team believes in you, it’s a combination of all those things.”

Pierce scored Boston’s first nine points but struggled mightily through the second and third quarters. He came through when the Celtics really needed him, especially with the Rondo-less offense a bit out of sync and Ray Allen sitting out again because of an injured right ankle.

Down the stretch, the Celtics simplified things: Give the ball to Pierce and get out of the way.

“Paul was great,” Celtics Coach Doc Rivers said. “The only way we were going to win a game like this without Ray and Rondo was if Paul had a game like this.”

After making a couple foul shots with just over a minute remaining to clinch it, Pierce paused on his way back to the bench and copied the move named after NFL quarterback Tim Tebow, sinking to a knee and bowing his head for a brief prayer in the middle of the court.

“You just want to thank God for putting you in those positions,” Pierce said. “It wasn’t pre-scripted. It just came to me.”

The Hawks appeared to be in control when they pushed out to a 65-54 lead late in the third quarter. But Boston sliced it to 66-61 by the end of the quarter, and Pierce led a dominating fourth.

In wiping out the double-figure deficit, Pierce outscored the Hawks 18-15, including 13 points in the final quarter. That was more than he had in all of Game 1, when Atlanta held Pierce to 12 points on 5-of-19 shooting.

“We expected him to come out and be aggressive offensively,” Hawks Coach Larry Drew said. “He got going early.”

The Celtics were up 74-72 when a quick spurt essentially finished the Hawks.

Joe Johnson committed a turnover, part of another tough game for the Hawks star, sparking a fast break that ended with a give-and-go from Avery Bradley to Pierce for a dunk. Jeff Teague then missed badly on a jumper, and Pierce hit his first 3-pointer of the series after missing 10 straight, stretching the lead to 79-72 with 3½ minutes left.

Pierce also led his team in rebounding with 14. Garnett had 15 points and 12 rebounds, while Bradley, who shifted over to take Rondo’s spot at the point, chipped in with 14 points but only three assists — a far cry from what the Celtics usually get out of that position.

Johnson had 22 points but never got many open looks, hitting just 7 of 17 from the field. Josh Smith had 16 points and 12 rebounds, but left late in the game because of a knee injury. The state of his knee now becomes a major concern for the Hawks, who already have played most of the season without Al Horford.

Smith will be re-evaluated today.

“He is one of our go-to guys down the stretch,” Drew said. “We were missing all of the things he brings to the table for us, especially down low.”

The Hawks made 4 of 19 shots in the final quarter, missing all four of their 3-point attempts. They also turned it over five times.

“We wanted that one at home,” Teague said. “We’ll have to go on the road and try to get the next one.”