The Boston Celtics took their sweet time to bring playoff intensity to the TD Garden Friday night, so when Ray Allen checked in to make his return with 4:39 left in the first quarter, he provided a restless crowd with its first real opportunity — after one slightly overzealous M-V-P chant for Paul Pierce — to work its collective lungs.

The crowd rose to its feet and roared in appreciation for the return of its fallen hero. Allen politely waved in response, then displayed what Celtics fans were hoping — that he’s still Ray Allen, if not the best shooter alive then at least in the conversation. The Atlanta Hawks almost looked as if they were accomplices to the moment, leaving Allen wide open in the corner almost as soon as he walked onto the court. He caught the pass, rose into his Kodak-moment form, and drilled a 14-footer from almost behind the backboard.

As Paul Pierce said, “Just having him out there really picked us up because we haven’t seen Ray in a jersey in so long. Just having him out there — you heard the reaction from the crowd when he checked into the game. Stuff like that brings so much energy to the ball club, to have a guy that’s so vital come out there and give us a big lift. It’s huge having him out there, especially tonight with Avery (Bradley) going down.”

If Celtics fans could take solace from the ugly victory, part of it was that Allen’s ankle did not seem to bother him. Doc Rivers admitted Allen might have to miss some more time during the playoff run and Allen said the ankle was “mad at me a little bit” after Boston’s 90-84 win. The pain won’t go away, not for the remainder of this postseason at least. But on night’s like last night, when the swelling subsides enough to allow Allen to compete, he can still be effective.

“In just the last two days, it’s been like night and day for me,” Allen said. “Being able to get into my routine — I’ve been so off my routine for the past two months. It’s like me, who I am. It’s been tough, you are almost from the outside looking in trying to be a part of the team and trying not to be in the way. Being back on the floor, I felt alive. I felt like I was back in my own skin and it was a great feeling.”

Allen played 37 minutes, far more than the Celtics probably expected, even if Rivers said prior to the game that the guard would have “no restrictions.” He didn’t hit a three-pointer on the night, finishing 0-4, but those will fall. Some of the misses were just off. Still, he finished 6 of 12 shooting from the floor for 13 points to go along with six rebounds.

Celtics fans probably watched with their hands trembling, halfway split between “RAY ALLEN’S BACK AND LOOKING LIKE RAY ALLEN!! I KNOW IT’S NIGHTTIME BUT IT DEFINITELY FEELS LIKE THE SUN IS SHINING!!!” and “man, if Allen’s ankle couldn’t handle his pregame routine two days ago, I can’t imagine how it’ll respond to 37 minutes of NBA playoffs intensity.”

Rivers admitted afterward that he wished his nucleus hadn’t played so many minutes. But with Avery Bradley ailing and the Hawks making a late charge to send the game into an extra session, the Celtics coach needed to rely on the guys he trusts, even the one with a balky ankle.

Plus, Rivers joked, he needs to get a lot of Allen while he still can.

“”Like I told you before the game — someone asked me, ‘Would there be a minute restriction?’ I said, ‘ No, because we don’t know when he’ll play again or not,’” Rivers said. “I’m saying that jokingly, but somewhat true as well.”

Yes, sadly for the Celtics, it’s somewhat true. Allen has felt better in the past couple days, but he knows the bone spurs are an issue he will have to deal with daily.

“I know mine is real and it still is real but I’ve gotten to a point where I’m able to handle it a little bit better than maybe a week ago. From day to day sometimes I haven’t known kind of how it was going to affect me so in the last two or three days it’s probably been the best it’s been. And I’ve been doing some things to help ail the pain I’ve been feeling in my ankle and it’s been great,” Allen said.

He added, “From day to day I don’t know some days. Trying to give you guys answers is sometimes hard to really explain or give answers, so it’s been great and I’m happy to be able to say that. And tomorrow’s a new day, but again I’m not going into it looking like or feeling like a victim. I’m coming out of the sand thinking it’s going to be good tomorrow and it’s going to be even better Sunday.”

Maybe it won’t be even better Sunday. Maybe his swelling will return Saturday morning. Maybe 37 minutes was too much. Maybe his contributions will be sporadic the rest of the way.

But he’s not 2011 Shaq. He’s not 2009 KG. He returned to the lineup, on a night where it turned out the Celtics could really use him, and provided a big boost.

“Tonight, honestly, we needed him,” Rivers said. “It’s amazing the difference when he’s on the floor in our spacing, and how much more difficult it is for guys to help.”

After three weeks of “will he play or won’t he play?” discussion, it’s nice to know Ray Allen can still be Ray Allen, at least on the nights his ankle behaves.