BOSTON – Maine and Boston University went into Sunday night’s Hockey East clashing realizing how important it would be to get the first goal, especially in the wake of Saturday’s scoreless tie.

In retrospect, the BU Terriers will look back on their second goal as the one that had the greatest impact.

BU’s Steve Thornton scored off a scramble in front of the net, breaking a 1-1 deadlock and igniting a three-goal, second-period outburst that sent Boston University on its way to a 5-1 Hockey East victory at Walter Brown Arena on Sunday night.

Maine slipped to 11-15-4 overall, 6-10-4 in league play. BU is now 21-7-1 and 14-4-1, respectively, and overtook UMass-Lowell for the lead in the Hockey East standings.

With the victory, BU won the season series against Maine for the first time since 1985-86.

BU coach Jack Parker said that while the initial goal was good, he went into the contest worrying about getting the second goal.

“I think the second is the most important one,” Parker said. “If they get one, we’ve got to make sure we tie it up 1-1 and if it’s 1-1, we’ve got to make sure we get the next one, because sooner or later, somebody’s going to score.”

The Terriers snapped the weekend’s scoreless streak late in the first period. It was the first tally in more than 83 minutes of play in the series.

Jon Jenkins broke into the scoring column thanks to a virtual collapse that enabled BU to negotiate a 4-on-1 rush. Rich Brennan carried down the right wing and slid a pass into the slot, where at least two Terriers were in position to make something happen.

Jenkins wasted no time, snapping a high, 10-footer over Blair Allison’s glove hand and touching off a huge roar from the crowd. The goal was the first for BU in 91 minutes of action.

Junior goaltender Derek Herlofsky turned in a 38-save performance, making 26 over the first two periods, to backstop the win.

Maine suffered two key losses 1:15 into the third period when freshman goaltender Blair Allison suffered strained ligaments in his left knee when he collided with teammate Jason Weinrich and was pinned against the goalpost.

Weinrich, who suffered a posterior cruciate tear in his right knee earlier this season, appears to have suffered a tear in his medial collateral ligament. Walsh, who voiced his concern about the injuries, didn’t dwell on the negative aspects of the loss.

“It was a real deceiving score. We had plenty of scoring chances and didn’t capitalize, and they did,” said Walsh, who noted BU’s ability to feed off the emotion of their two key goals.

“Those goals were adrenalin-builders and then the two key moments where they had a second goal right after we tied it and they got the fourth goal with seven seconds to go (in the second period).”

Once the double goose egg had gone by the board, the scoring pace picked up. Maine tied it on the power play with 43 seconds gone in the second period.

Cal Ingraham, camped to the right of Herlofky, took the rebound of a Justin Tomberlin shot from the left point and fired it in to the short-right side. Maine previously had gone 91:39 without scoring.

The Terriers didn’t wait for Maine to get any momentum going. Just 34 seconds later, Steve Thornton stuffed a shot past Allison after he failed to cover a loose puck in the crease.

The hosts made it 3-1 at the 8:04 mark of the second period. Chris O’Sullivan picked off Andy Silverman’s errant clearing pass near the left point, moved in and slipped a pass to Jenkins, who was positioned at the left post and poked it home.

Pandolfo added a big blow for the Terriers with only seven seconds left in the period, cutting into the slot and one-timing a sweet feed from Mike Grier past Allison. That goal was the extra boost the Terriers needed to assure a victory.

“The crowd gets the (tired) legs going, that’s for sure,” Parker said. “This is one of the great buildings, noise-wise, and emotion’s a big part of a hockey game here.”

The third period was marred by chippiness and numerous penalties.

Goalie Blair Marsh had been in the game for 33 seconds when Pandolfo slipped a backhander between his pads, making it 5-1.

The Bears didn’t lack scoring chances in the first period, outshooting the Terriers 12-7. However, Maine failed to capitalize on a two-man advantage early that lasted a minute and 15 seconds.

Herlofsky picked up right where J.P. McKersie had left off the previous night. His best stop came when he stopped a Mike Latendresse shot off a 2-on-1 chance with Patrice Tardif.

Allison was equally impressive, kicking away some tough shots through crowds in front of the goal.

Terriers 5, Bears 1

Maine 0 1 0 – 1 Boston University 1 3 1 – 5

First Period – 1. BU, Jenkins 10 (Brennan, Rausch), 18:25; Penalties – BU, Coleman, hooking, 5:11; BU, Brennan, hitting from behind, 5:56; Maine, Wlasow, interference, 8:15; Maine, Cardinal, holding stick, 13:31; BU, Brennan, holding, 19:46

Second Period – 2. Maine, Ingraham 8 (Tomberlin, Tardif), :43; 3. BU, Thornton 9 (LaChance, Friedman), 1:17; 4. BU, Jenkins 11 (O’Sullivan), 8:04; 5. BU, Pandolfo 10 (Grier, Bates), 19:53; Penalties – Maine, Frenette, high-sticking, 12:40; BU, Johnson, holding, 12:40; Maine, Lovell, roughing, 14:58; BU, Thornton, roughing, 14:58; Maine, Wlasow, tripping, 16:54

Third Period – 6. BU, Pandolfo 11 (Bates), 1:19; Penalties – Maine, Marsh, tripping (served by Shermerhorn), 1:42; Maine, Frenette, late hit, 1:42; Maine, Texeira, roughing, 9:58; BU, Wood, holding, 9:58; BU, Brennan, slashing, 11:00; BU, Bates, roughing, 12:15; Maine, Shermerhorn, slashing, 12:15; Maine, Mahoney, interference, 14:00; Maine, Tardif, roughing, 14:20; Maine, Ingraham, high-sticking, 17:27; BU, Joubert, cross-checking, 18:15;

Shots on goal: Maine 12-15-12 – 39; Boston University 7-8-10 – 25

Goaltenders: Maine, Blair Allison, Blair Marsh; Boston University, Derek Herlofsky