NEW YORK – When Rangers coach John Tortorella scratched former Conn Smythe Trophy winner Brad Richards for Game 4, the buzz surrounding the announcement drew more attention than Tortorella’s 19-second press conference at the morning skate. That, and defenseman Roman Hamrlik replacing the injured Anton Stralman left the Blueshirts in a vulnerable position.

The Bruins had the Rangers on the ropes and eyed their second Eastern Conference Finals appearance in three seasons. But, despite a solid start, they could not complete the sweep.

A series of blunders cost the Black and Gold in their 4-3 overtime loss to the Blueshirts in Game 4 Thursday night at Madison Square Garden. More importantly, it gave the Rangers new life.

“We made mistakes and they capitalized on their chances,” a dejected Zdeno Chara said afterwards. “We have to eliminate those and get ready for the next one.”

It all started when the B’s led 2-0 and had momentum on their side thanks to second period goals by Nathan Horton and Torey Krug on the power play. But a costly play by Tuukka Rask shortly after Krug’s tally at 7:41 gave the Rangers new life. With a weak backhander by Carl Hagelin, Rask fell down and could not recover as the puck trickled past him to give the MSG crowd something to cheer about.

The trickle down effect continued in the third as Derek Stepan took advantage of turnover by Chara – behind Rask – and tied things up at 2-2 just 1:15 into the final stanza. Then, with a 3-2 lead thanks to Tyler Seguin’s first of the playoffs, the Bruins were called for a bench minor for too many men, which led to Brian Boyle’s tying goal with 10 minutes left in regulation.

Finally, in overtime, Dougie Hamilton was unable to stop Chris Kreider’s tip-in at 7:03 of the extra session.

“We gave them a couple of gifts and at the end of the day, that’s what cost us,” Rask said. “It’s a game of mistakes. A team makes mistakes and a player makes mistakes. We just have to learn from it and move forward. The mistakes we had doesn’t make us a bad hockey team. What happens, happens, and we have to shake it off and move on.”

Moving on is exactly what the Bruins need to do. But Thursday’s loss is another cause for concern.

Having already been through a similar situation in the first round against the Toronto Maple Leafs, the B’s need to regain that killer instinct and finish the series. They will get another chance to do that in Game 5 on Saturday as the series shifts back to the TD Garden.

“That’s one you want to take,” said Seguin, who also took responsibility for the too many men penalty. “We had the opportunity to win [tonight] and we thought we had played well on the road, especially last game [Game 3]. It would have been nice to get out of here with a win, but again, we’re going to go on to our home ice and play a better game.

“It’s a fresh new start here. It doesn’t matter what happened in this series. We have to be better.”