Already ahead 3-2 going into the third period, the Boston Bruins wasted little time displaying a killer instinct.

Just 24 seconds into the final stanza, Brad Marchand put the B’s ahead 4-2 with his second of the playoffs. Milan Lucic delivered the dagger in late in the third period, as Boston put a 5-spot on Henrik Lundqvist.

That third period was a lot more than the two goals from Marchand and Lucic. It was about keeping the foot on the gas pedal and putting the New York Rangers in a hole.

That’s exactly what they did.

“We talked about it in the third period, and we just wanted to make sure that we played to win,” head coach Claude Julien said following Sunday’s 5-2 victory. “I didn’t want our guys playing on their heels, and you hear me say that a lot. I don’t like our team when we play on our heels and we’re just trying to protect a one-goal lead. We’ve got to extend the lead and extend it even more before we even think about protecting it.

“But our guys are smart. They put pucks at the net, they went to the net hard, we won battles for loose pucks and we found a way to score those goals. Those little details are what gave us the opportunity to win those important games.”

Now that they are ahead 2-0 in the best of seven, the Black and Gold need to finish the job and not give the Blueshirts any hope as the series shifts back to Madison Square Garden for Game 3 tomorrow night.

It’s no secret that the Bruins have had some problems displaying that killer instinct. Just look at their first round series against the Toronto Maple Leafs, where they were forced to play a seventh and decisive game despite having a 3-1 series lead.

This script was written before, however. After Nathan Horton’s winner against the Montreal Canadiens two years ago in Game 7 – a day after the Habs forced a seventh game – the Bruins faced a Philadelphia Flyers team that was vulnerable due to injuries and shaky goaltending. Smelling blood, Julien’s squad swept the series in the second round just 12 months after their historic collapse against the Broad Street Bullies.

Like the Flyers in 2011, the Rangers have their share of issues that they need to address. Despite his goal in Game 2, Rick Nash is still trying to get going offensively, while former Stanley Cup Playoff MVP Brad Richards is now relegated to fourth line status. Their defense, especially Michael Del Zotto and Dan Giardi (who were a combined minus-7 in Game 2), is letting Lundqvist hung out to dry.

The Rangers also trailed 2-0 against the Capitals and found a way to win their first round series in seven games. That’s something the Bruins want to avoid at all costs and it can all start with a Game 3 victory.

“They were down 2-0 in their last series and we know we can’t take them lightly,” Marchand said. “We got to make sure we go to New York very hungry and ready to go out hard.”

Complacency is always a trait that a team wants to avoid. Having learned this from the Leafs series, the Bruins know they have to get another 60-minute effort Tuesday night in order to take a three games to none lead and put the Rangers on the brink.

“You can’t take anything for granted right now. It’s [the] playoffs. Anything can happen, and sometimes a team can play better in front of their hometown and we don’t expect them to lay down,” said defenseman Johnny Boychuk, who scored the go-ahead goal at 12:08 of the second period in Game 2. “We expect it to be very physical and demanding next game, and we know that they’re going to be ready.”