BOSTON, Mass. -- Harvard erupted for six goals, three by Luke Greiner, as the Crimson rallied to knock off No. 13 Boston University 7-4 on Monday in the Beanpot consolation game at TD Garden.

The Crimson fell behind by scores of 2-0 and 3-2, but battled back behind four consecutive goals in the second and third periods to defeat the Terriers twice in a season for the first time since 1979-80.

Senior Luke Greiner recorded his first career hat trick in his final Beanpot game, and classmate Marshall Everson scored two goals to pace the Harvard offense. Captain Danny Biega, who had one assist, and Dan Ford scored to erase a two-goal, first-period deficit. Kyle Criscuolo added two helpers.

The Terriers struck quickly, getting on the board with 16:48 and 8:15 left in the first to take a 2-0 lead, but the Crimson answered shortly thereafter to swing the momentum in its favor.

Just moments after a power play expired and 79 seconds after BU's second goal, Harvard found the back of the net as Criscuolo picked up the puck behind the cage and sent a backhand off the front of Sean Maguire's pads. Ford skated across the face of the crease, picked up the rebound and flicked it into the upper left corner of the net.

Harvard knotted things up in the waning moments of the period on Biega's second goal of the tournament. He recovered from getting checked into the nearside boards and kept a BU clear attempt in the zone. After gathering the puck, he fired a shot over Maguire's glove to make it 2-all with 14.2 seconds left.

As the first period ended, Harvard was whistled for its fourth penalty of the game, and the Terriers capitalized after the intermission on an Evan Rodrigues slap shot.

Harvard drew even just more than a minute later. Criscuolo scooped up the puck behind the net and fed it to Everson camped in the slot. The senior sent it into the top right corner of the net for his second goal in as many days.

Harvard took its first lead of the game more than a minute later. Greiner sent the puck into the same spot that Everson scored from for a 4-3 advantage.

After going up by one, the Crimson killed off back-to-back penalties to maintain the advantage with Traber making an impressive glove save to keep the Terriers off the board during the four-minute span.

While the Terriers failed to capitalize on their man-up situations, Harvard made the Terriers pay after going back on the power play. Brian Hart blasted a feed from Biega that careened off Maguire's pads to Greiner's stick in front of the crease. He sent the puck high and to the glove side to push the lead to two.

The Crimson pushed across its sixth goal on another rebound, just moments after another BU penalty ended. After a cross-ice, backhand feed from Colin Blackwell, Fallstrom rocketed a one-timer that Maguire could not corral and that Everson cleaned up with his second goal of the game.

BU threatened in the remaining 17 minutes but only struck once, with a power-play goal with 8:36 remaining, as Traber continued to turn away BU shots and finished with a career-high 43 saves.

The Terriers attempted to mount one last rally, pulling Maguire with 1:04 remaining. Greiner took advantage and completed his hat trick with only 8.6 seconds remaining. He stole the puck in the BU zone and flicked it into the empty net for a short-handed goal to give Harvard its first seven-goal game since Nov. 22, 2011, when the Crimson rallied to defeat New Hampshire 7-6.