Philadelphia, PA (SportsNetwork.com) - Daniel Ciampini registered a hat trick as Union edged Boston College, 5-4, at the Wells Fargo Center to advance to its first NCAA championship game.
The Dutchmen (31-6-4), who have won a school-record 11 straight games and improved to 15-0-1 in their last 16 games, eliminated Boston College (28-8-4) from the NCAA Tournament for the second straight year.
Union will play the winner of the second national semifinal between former WCHA rivals Minnesota and North Dakota on Saturday.
Ciampini broke a 2-2 tie at 6:31 of the third period by deflecting defenseman Shayne Gostisbehere's one-timed blast for a power-play goal.
Eighteen seconds after Ciampini's tiebreaking goal, Dutchmen forward Matt Hatch received a five-minute major and a game misconduct for hitting BC's Michael Sit into the boards from behind.
Union, making its second appearance in the Frozen Four in three years, scored on a takeaway right after killing the lengthy power play. Eagles goaltender Thatcher Demko turned away Kevin Sullivan's shot, but Sullivan gathered the rebound and chipped it out front. An uncovered Mike Vecchione then hammered the puck into the open cage to make it 4-2 at 11:53.
Boston College got a goal from Ryan Fitzgerald with Demko on the bench for an extra skater at 18:15 before Ciampini completed the trifecta with an empty- netter with 1:09 left.
The Eagles, who had won the national title in each of the previous three even- numbered years, continued to fight and Patrick Brown scored a power-play goal with 4.3 seconds remaining.
Union goaltender Colin Stevens was forced to make one final save as he denied Boston College star forward Johnny Gaudreau prior to the horn.
The Eagles' dynamic top line of Gaudreau, Kevin Hayes and Bill Arnold opened the scoring 2:08 into the contest. Hayes made a nice move to the net after taking a pass from Arnold and fired a shot that was stopped in the crease, but Gaudreau, a finalist for the Hobey Baker Award, collected the puck in the blue paint and scored on a backhander.
Union scored two second-period goals to grab the lead before Boston College tied it late in the middle stanza.
Defenseman Mat Bodie beat Demko high on the far side with a slap shot from the top of the right circle at the 2:39 mark.
The Dutchmen continued to pepper the Boston College freshman and moved ahead at 10:45 after winning an offensive-zone faceoff. Gostisbehere, playing on the home ice of the Philadelphia Flyers, the club that selected him in the third round of the 2012 NHL Entry Draft, fired a soft wrister from the right point that Demko couldn't cleanly catch. The high shot went off the goalie's glove and Ciampini buried the rebound.
Boston College pulled even on Steve Santini's goal at 15:53. In transition, Chris Calnan hit Santini, who joined the rush late, with a pass and the defenseman scored on a shot from high in the right circle.