Every Knick wore black to the arena, and not because they decided to have a Johnny Cash theme night.

For all of the talk coming from the other side about graveside fashion and tee times, the Celtics came out committed to avoiding a seat in the coffin in last night’s 92-86 Game 5 win.

J.R. Smith, who had a shovel in one hand and his driver in the other, suddenly felt cheated.

“We (were) going to a funeral, but it looks like we got buried,” said the Knicks forward, who returned from a one-game suspension as the old J.R., the one all-too happy to launch his shots from North Korea.

He didn’t hit his first shot until the fourth quarter, finished 3-for-14 from the field and wasn’t good for much more than a late score.

As a result, the Celtics not only avoided a return of the Knicks’ dreaded balance, they responded with their best distribution of the series. Five Celtics scored between 16 and 18 points, and Kevin Garnett grabbed 18 rebounds, giving the Celtics center 52 in his last three games.

This appears to be a team on the rise, though like someone frightened by their shadow, the Celtics are petrified of looking any further ahead than the next possession. It appears to be working.

It helps when the grave diggers don’t collect their pay.

“You’re only buried if the casket is closed,” said Jason Terry. “Us getting that win (in Game 4) opened the door a little bit; winning tonight opens it a little bit more. If we can even this thing up, it’s anyone’s series. We have to come out every possession, every quarter and really try to win. That’s been our focus since we were down 3-0. We talk about can we win every quarter?”

The comeback talk, not so much from the Celtics, followed, but Garnett was having none of it. He still sees a one-game deficit. For public consumption, anyway, he doesn’t feel like momentum has shifted.

“We’re still down, but our mentality has to be all out,” said a particularly reserved Garnett. “We’re down 3-2, the next game we lose is it, so I don’t know why everyone is talking about getting comfortable. We’re down 3-2. It’s not like we evened it up and we’re going home. We’re down 3-2.”