ORONO – The University of Maine’s power play has certainly had its share of struggles this season, going 2-for-40 during one recent stretch.

But it came through at a crucial time as the Black Bears, hungry for wins in their quest to earn a seventh straight NCAA Tournament berth, used three power-play goals to beat Boston University 4-2 before a sellout crowd of 5,641 at the Alfond Arena Saturday night.

Maine’s penalty-killing unit, seventh best in the nation (87.2 percent success rate), also did the job, thwarting all seven BU opportunities.

“Going down the stretch, we know special teams are going to be huge. You have to outwork teams on the special teams. We didn’t do that [Friday] night (in a 1-1 tie) so that was one of our objectives tonight and we did it,” said Maine junior goalie Jimmy Howard, who finished with 28 saves including 11 off Grade-A (high-percentage) shots.

“Maine played great on the power play and that was the difference in the game, obviously,” said BU coach Jack Parker. “They played great both on the penalty kill and the power play.”

Sophomore right wing Keith Johnson, who chose Maine over BU, where his brother Gregg played until graduating last year, collected the second two-goal game of his career and first since Oct. 18, 2003 against Holy Cross. Both goals came on the power play.

Johnson said the Maine-BU series is one of the biggest rivalries going and he knows a lot of the BU players through his brother.

“It definitely feels good to contribute to a win,” said Johnson.

Maine improved to 13-8-5 overall and 8-3-3 in Hockey East. The Bears extended their unbeaten streak to five games (3-0-2) and they are now 5-0-2 over their last seven games at Alfond Arena entering next weekend’s home series with Northeastern University.

BU fell to 13-10-1, 9-4-1 in Hockey East, and the Terriers had their winless streak expanded to four games (0-3-1).

Jon Jankus and BU’s Dave Van der Gulik swapped first-period goals before Johnson put the Bears ahead for good in the second period.

Johnson made it 3-1 just 1:20 into the third period but BU freshman right wing Bryan Ewing answered just 37 seconds later.

The Terriers stormed the Bear net looking for the equalizer but Howard made several critical saves among his 13 in the period and junior right wing Greg Moore secured the win on the power play with 3:24 remaining, extending his goal-scoring streak to four games in the process.

“After they got within one, they kept coming but we buckled down and got the job done,” said Howard, who made two rapid-fire saves on Brian McConnell with six minutes left.

McConnell tipped a Sean Sullivan point shot and then pounced on the rebound.

“I didn’t see the shot all the way but I saw the tip and got my pad on it,” said Howard. “He got the rebound but, luckily, I got over and got another pad on it.”

“Howard played real well in the third period,” said Parker. “McConnell was on the doorstep a couple of times but didn’t deposit it [into the net].”

Jankus opened the scoring when his wrister off a Moore rebound glanced into the net off BU’s Chris Bourque, who dove to try to cover the half-empty net.

Van der Gulik drew the Terriers level with 3:10 left in the period by coming out of the corner to Howard’s left and jamming home his third rebound.

Johnson broke the tie when he helped create a screen in front of BU goalie John Curry and tapped a rolling puck over the goal line after Bret Tyler’s wrister from the point hit Curry in the shoulder, popped in the air and bounced off his back.

“I think it was going in any way I just helped it over the line,” said Johnson.

His game-winner was created by his speed as Mike Hamilton chipped the puck into space along the left wing and Johnson skated on to it and beat a BU defenseman wide before cutting in and backhanding a 12-footer inside the far post.

“I didn’t have much to shoot at. I was just trying to get it on the pads because I knew [Derek] Damon was coming far post to try and get a rebound,” said Johnson.

“I’m not sure how that went in. It might have hit my pad or stick,” said Curry.

Ewing answered quickly by snapping his own rebound between Howard’s glove and his body but Moore iced it when he wristed home a 25-footer from the high slot after Jankus’ shot from the point was blocked and deflected fortuitously over to him in the high slot.

“I put it low, right side,” said Moore.

“Things like that tend to happen when you have a team like [Maine] that plays with a lot of energy. They’re flying around and with this crowd behind them, it’s a real advantage for them,” said Curry, who made 26 stops (10 Grade-A’s) including two off breakaways in the last 1:15 of the second period.

BLACK BEARS 4, TERRIERS 2

Boston Univ. (13-10-1) 1 0 1 – 2

Maine (13-8-5) 1 1 2 – 4

First period – 1. Maine, Jankus 7 (Moore), 7:51; 2. BU, Van der Gulik 11 (Zancanaro), 16.50. Penalties: Maine, Zabkowicz, obstruction interference, 5:40; BU, Spang, holding, 9:17; BU, Curry, roughing (served by Monaghan), 10:20; Maine, Shepheard, slashing, 10:20; Maine, Moore, interference, 10:52; BU, Miller, hooking, 12:30; Maine, Jankus, tripping, 14:11; Maine, Ronan, contact to head roughing, 18:10.

Second period – 3. Maine, Johnson 5 (Tyler, Damon), 2:19 (pp). Penalties: BU, Miller, tripping, 1:07; Maine, Zabkowicz, contact to head elbowing, 3:12; BU, McConnell, contact to head roughing, 10:25; BU, Laliberte, obstruction interference, 15:36; Maine, Moore, hitting from behind, 17:40; BU, Monaghan, contact to head high-sticking, 19:48.

Third period – 4. Maine, Johnson 6 (Tyler, Hamilton), 1:20 (pp); 5. BU, Ewing 2 (MacArthur, Miller), 1:57; 6. Maine, Moore 11 (Leveille, Jankus), 16:36 (pp). Penalties: Maine, Johnson, holding the stick, 3:47; BU, Schaeffer, contact to head high-sticking, 16:12.

Shots on goal: BU 11-5-14-30; Maine 13-12-5-30

Goaltenders: BU, Curry (30 shots-26 saves); Maine, Howard (30-28)

Power-play opportunities: BU 0-7; Maine 3-7

High-percentage scoring chances: BU 7-3-10-20; Maine 8-4-5-17

Attendance: 5,641 (sellout)