NORTH ANDOVER, Mass. – The No. 1-ranked University of Maine Black Bears entered Friday night’s Hockey East game against Merrimack College with the nation’s second-best power-play efficiency rate (27.3 percent).

They improved that percentage against the Warriors, receiving all four goals with the man advantage en route to a 4-1 win over Merrimack.

Maine is now 7-0 overall, 2-0 in Hockey East. Merrimack fell to 1-5-1 and 1-2, respectively. The record matches Maine’s best start ever of 2003-04.

Maine visits Boston University tonight.

Mike Lundin and Keith Johnson scored 1:55 apart midway through the second period to snap a 1-1 tie after Maine’s Brent Shepheard and Merrimack’s Pat Kimball swapped first-period goals.

Josh Soares added an insurance goal 6:07 into the third period.

“Our power play struggled last weekend [0-for-3 vs. UMass], so we focused on just keeping things simple tonight,” said Soares. “We moved it quickly and got the puck to the net.”

Lundin broke the tie 9:45 into the middle period after Michel Leveille and Purcell criss-crossed in the high slot. Leveille passed it to Purcell and Purcell threw it across to an uncovered Lundin at the right point.

“Teddy went to the middle and the guy who was on me went over to him. A guy came out at me and I just tried to get it through him. It wound up going through three guys,” said Lundin.

Merrimack goalie Jim Healey said he didn’t see it until the last second.

“It went low blocker side. I tried to stretch over, but I couldn’t get there,” said Healey.

Moments later, Leveille fed Purcell at the midpoint and the freshman took a quick wrister that was tipped by Soares.

“I made the save and tried to clear the rebound, but Johnson was at the back door,” said Healey.

“It landed on my stick and I put it short side,” said Johnson.

Maine had five of its 10 power-play chances in the second period and outshot Merrimack 22-3.

Healey kept the hard-working and youthful Warriors in the game with several quality saves.

“We took too many penalties,” said Healey.

Soares gave Maine some breathing room after a four-on-two enabled Purcell to stickhandle to the netfront and take a point-blank shot on fellow Newfoundland native Healey, who made the save under his arm only to have the puck drop in the crease.

“I just one-handed it in,” said Soares.

Shepheard had opened the scoring by tipping a Bret Tyler shot past Healey, but Kimball equalized by tucking a 15-footer along the ice past Maine goalie Ben Bishop during a scramble.

Bishop finished with 15 saves in improving his record against Merrimack to 4-0. He has allowed four goals in those wins.

“I thought I played well. Whenever you win, you’ve got to feel happy,” said Bishop, who made some solid saves in the third period to prevent the Warriors from gaining momentum.

“It’s always good to get two points on the road. It’s tough to do,” said Johnson.

Leveille said the Warriors’ passive forecheck made it difficult for Maine, especially in the first period, but the Bears persevered.

Purcell finished with three assists for Maine.

Merrimack coach Mark Dennehy was upset at the disparity in power-play chances through the first two periods. Maine had nine to his team’s three.

“It is what it is,” said Dennehy. “Everybody in the rink saw it.”

Healey finished with 34 saves.

Maine is now 13-0-2 in its last 15 games against Merrimack.

Merrimack went 0-for-4 on the power play.

“Our penalty killing was sharp,” said Maine coach Tim Whitehead.

BLACK BEARS 4, WARRIORS 1

Maine (7-0-0) 1 2 1 – 4

Merrimack (1-5-1) 1 0 0 – 1

First period – 1. Maine, Shepheard 3 (Tyler, Duffy), 9:12 (pp) 2. Mmk, Kimball 2 (Alexiou, Robitaille), 14:22. Penalties: Maine, Danis-Pepin, hitting from behind, 1:15; Mmk, Rego, obstruction-interference, 4:01; Mmk, Byrnes, holding, 7:19; Mmk, Bowen, contact to the head-roughing, 9:29; Maine, Tyler, high sticking and hitting after the whistle, 16:25; Mmk, Wilson, hitting after the whistle, 16:25; Mmk, Vaskivuo, high sticking, 17:02; Maine, Danis-Pepin, hitting from behind, 19:23

Second period – 3. Maine, Lundin 2 (Purcell, Leveille), 9:45 (pp); 4. Maine, Johnson 3 (Purcell, Soares), 11:40 (pp). Penalties: Mmk, Nugent, roughing, 3:21; Mmk, Wilson, slashing, 7:46; Mmk, Robitaille, holding, 11:19; Maine, Duffy, hitting after the whistle, 11:19; Mmk, Bowen, roughing, 11:19; Mmk, Jones, contact to the head-elbowing, 12:21; Mmk, Bowen, roughing, 12:21; Maine, Duffy, hitting after the whistle, 12:21; Mmk, Byrnes, cross checking, 13:06; Maine, Johnson, hitting after the whistle, 16:34; Mmk, Hart, hitting after the whistle, 16:34; Maine, Clark, hitting after the whistle, 19:49; Mmk, Byrnes, hitting after the whistle, 19:49

Third period – 4. Maine, Soares 3 (Purcell, Johnson), 6:07 (pp). Penalties: Mmk, Bowen, bench minor (too many players on ice), 5:54; Maine, Hamilton, charging, 9:28; Maine, Shepheard, 5-minute major (hitting from behind), 16:15; Maine, Hamilton, hitting after whistle, 19:25; Mmk, Jones, cross-checking, 19:25

Shots on goal: Maine 9-22-7-38; Merrimack 4-3-9-16

Goaltenders: Maine, Bishop (16 shots-15 saves); Merrimack, Healey (38-34)

Power-play opportunities: Maine 4 of 10; Merrimack 0 of 5

High-percentage scoring chances: Maine 11-18-3-32; Merrimack 4-5-9-18

Attendance: 2,597