The energy was spurred by negativity, by a play that by all accounts should not be part of the game.

But last night at the Garden, it was a shove from the Sabres’ Patrick Kelata to the small of Brad Richards’ back early in the third period, sending the Rangers’ alternate captain face-first into the boards and to the ice writhing in pain, that lit a fire underneath the once-dormant Blueshirts.

Kaleta earned a five-minute, checking-from-behind major and a game misconduct, and Richards returned to the game as his team rallied for a 3-2 shootout victory.

“It’s probably one of the most dangerous hits I’ve seen,” said coach John Tortorella, foreseeing the meeting between Kaleta and league disciplinarian Brendan Shanahan just hours away. “Same guys. Jesus Christ. That’s what I thought of it.”

The hit came with the Rangers (10-8-2) on the power play, 3:28 into the third period and the Sabres (9-12-2) up 1-0. Kaleta approached Richards’ turned back near the sideboards and gave a clear shove with his stick parallel to the ice, Richards’ head bending with his neck and shoulder slamming into the boards.

“I didn’t have a lot of thoughts,” Richards said. “I was just trying to breathe.”

Seven seconds into the ensuing 5-on-3, Rick Nash made a wonderful cross-ice pass to Derek Stepan, who tied the game 1-1. Just 43 seconds later, Nash got open at the right circle and tore a wrist shot underneath Ryan Miller’s right arm, making it 2-1.

“Yeah, that’s great, I’m glad we made them pay,” Tortorella said. “It’s disgusting. It’s a lack of respect. Each team wants to beat the other team, but you need to respect what’s going on on the ice.”

Richards wasn’t too far behind his coach in the level of frustration.