NHL

Rangers defeat Senators in playoff opener

Brian Boyle celebrates his second-period goal with Dan Girardi. (Anthony J. Causi)

For a significant stretch through the first 30 minutes of last night’s first-round playoff opener at Madison Square Garden, the only way to truly identify the top seed was by the color of the uniforms denoting home and away.

But, critically, Henrik Lundqvist was wearing the Blueshirt, and when the King refused to be beaten even as his team spent shifts at a time in the defensive zone through the midway point of the second while trying to protect a one-goal lead, the Rangers grabbed onto his cape and steadied themselves to record a 4-2 victory over the Senators for the jump in the best-of-7 that continues at Madison Square Gaarden tomorrow night.

“They’re a good team, a skilled team, they’re going to come hard, and they did, but when they do it’s important that we don’t get hurt,” Lundqvist said after a 30-save performance during which he held Ottawa scoreless until the 10:05 mark of the third. “We can’t be in control for 60 minutes, but we have to remain committed to playing our game even when things are not going our way.”

The Rangers did that even through a stretch in which they iced the puck six times in the opening 9:51 of the second, maintaining their composure if not possession following a first period from which they emerged with a 1-0 lead on a Ryan Callahan goal.

“We’ve talked all year about handling momentum swings and even though we got caught out there a few times and gave up some chances, we didn’t give up a lot of glorious chances,” Marc Staal said. “And when they got their best chances, that’s when Hank was at his best.

“He allowed us to catch our breath and get our game back.”

Lundqvist faced flurries of shots early in the period when the Rangers were caught in a terribly unfavorable matchup with the Mike Rupp-John Mitchell-Brandon Prust unit on against Ottawa’s Nick Foligno-Kyle Turris-Daniel Alfredsson unit. He made a huge stop to preserve the lead when Jim O’Brien broke in alone 9:01 into the period.

“We handled the momentum shifts in the second when they could have tied it, but we don’t want to have to rely on Hank for that amount of time all at once,” said Brad Richards. “He’s going to have to make big saves because they’re a good team, but need to have more [offensive] zone time that we did in the second.”

Coach John Tortorella called a timeout after his team’s sixth icing at 9:51. The Rangers grabbed control immediately thereafter, with the Richards-Marian Gaborik-Carl Hagelin line upping the tempo following a quiet first 30 minutes.

“The three of us had a chat on the bench after the timeout about holding on to the puck and trying to get something going,” Richards said. “Then when we generated scoring chances, we started to get more relaxed with the puck.”

There was a questionable tripping penalty called on Ryan McDonagh at 12:56 that provoked Lundqvist into screaming at referee Dan O’Halloran before the goaltender voluntarily silenced himself.

“I caught myself and told myself there was too much work to do, so I had to remain calm,” Lundqvist said. “Even though I was upset, I had to stay focused.”

Lundqvist remained focused. The Rangers killed the penalty and exploded soon after to gain a 4-0 lead with Gaborik making it 2-0 at 16:24, Brian Boyle extending it to 3-0 at 19:06 and then Richards capping it at 2:15 of the third before Ottawa scored twice.

“We have work to do, but to get the first one is a good feeling,” Lundqvist said. “It’s good for our confidence.”

It’s about as good for the Rangers’ confidence as having Lundqvist’s cape to grab hold of.

larry.brooks@nypost.com