SCHENECTADY -- Lightning doubled back on Saturday night.
A year after Union's Mike Vecchione ended Princeton's season at Messa Rink with an overtime penalty shot in the playoffs, the Tigers' David Hallisey ended the Dutchmen's 2017-18 season at Messa by finishing a 3-on-1 break with 9.5 seconds left in regulation.
The game appeared to be headed to overtime, but Princeton (17-12-4) put together one more surge up ice to break a 2-2 tie late and advance to the ECAC Hockey semifinals next weekend in Lake Placid.
The Dutchmen (21-15-2), meanwhile, were ousted as the second seed on the heels of a regular season that exceeded expectations, only to be snuffed out in a best-of-three quarterfinals sweep by Princeton in dramatic fashion.
"Last year, they lost. They were a little hungry," Union head coach Rick Bennett said. "Sometimes you've got to lose to win. We know that here.
"I'm not saying we weren't hungry. I'm happy for the season we had. But the playoffs is a different animal."
"It's different in college hockey," Princeton head coach Ron Fogarty said. "Your memory's short, because you have new teams, and everyone grows and matures and gets stronger.
"We were really focused on the task at hand, and whatever happened last year is irrelevant. As a staff, you have a little bit longer memory. I was hoping to win last year, but for a couple breaks against [Spencer] Foo and Vecchione; I believed we could win this year."
The Tigers led 2-0 after the first period, but the Dutchmen came storming back and carried the play for much of the second and third periods.
Union was wary of Princeton's skill at making quick transitions from defense to offense, and that ability was never more evident than on the game-winning play.
Dutchmen senior defenseman J.C. Brassard stepped forward to keep the puck inside the offensive blueline, but couldn't contain it as the Tigers rushed up ice on a 3-on-1 in the closing seconds. Vas Kolias did what he could to break up the play, but Hallisey was left alone in front of the net and buried the game-winner past goalie Jake Kupsky with 9,.5 seconds left, leaving the Dutchmen doubled over in shock and disappointment.
"Huge win for our team," Hallisey said. "Really excited. We've been waiting for one of those for awhile."
"Against that team, you better watch your line changes," Bennett said. "It was an 'O' zone turnover, and we pinched, they got by us and had a 3-on-1. It's a 3-on-1. With not much time left.
"I thought Vas did a great job of taking it away, too. He took two guys away. All the guy had was the short side, Jake made a great save, but we didn't funnel to the net properly. Their guy stops at the net, and it's game over. It was just too easy."
Princeton took a 2-0 lead in the first period on a pair of break-ins behind the Union defense.
Max Veronneau sent in Alex Riche for a rush on Kupsky, and his goal made it 1-0 at 14:44, followed by another goal in transition by Eric Robinson just over four minutes later while the Tigers were short-handed.
Joe Grabowski hit Robinson with a lead pass, and he was able to just muscle around defenseman Greg Campbell for a 2-0 lead at 18:49.
The Dutchmen carried the play during the second period despite a five-minute major penalty and game misconduct to Luc Brown for checking from behind at 9:25.
By then, the Dutchmen had tied it 2-2 on Anthony Rinaldi's 17th goal of the season at 7:53, and Ryan Walker's 11th goal just 1:14 later.
Union nearly took a 3-2 lead with just under a minute left in the second on a goalmouth scramble, but the officials waved it off after a quick review.
"That team was, overall, hungrier than us," Bennett said. "For two periods, we were a pretty darn good hockey club. But you're also playing a good hockey club."
Bennett is a finalist for ECAC Hockey coach of the year, along with Cornell's Mike Schafer and Clarkson's Casey Jones, and Kupsky is one of four finalists for goalie of the year. The others are Cornell's Matthew Galajda, Clarkson's Jake Kielly and Colgate's Colton Point.
Clarkson's Nico Sturm was named best defensive forward, and Cornell's Alec McCrea was named best defensive defenseman.
The rookie of the year finalists are Galajda, Clarkson's Jack Jacome and Quinnipiac's Odeen Tufto.
Princeton 2 0 1 -- 3
Union 0 2 0 -- 2
First period -- 1, Princeton, Riche 6 (Veronneau, Teves), 14:44. 2, Princeton, Robinson 15 (Grabowski), 18:49 (sh). Penalties -- Robinson, Princeton (roughing), 16:18; Vidmar, Union (roughing), 16:18; Hallisey, Princeton (holding), 17:47.
Second period -- 3, Union, Rinaldi 17 (Campbell, Kupsky), 7:53 (pp). 4, Union, Walker 11 (Scarfo), 9:07. Penalties -- Campbell, Union (boarding), 2:12; Riche, Princeton (slashing), 7:06; Brown, Union (checking from behind, major-game misconduct), 9:25.
Third period -- 5, Princeton, Hallisey 17 (Teves, Robinson), 19:50.
Shots on goal -- Princeton 12-4-6 -- 22. Union 6-15-10 -- 31.
Power-play opportunities -- Princeton 0 of 2. Union 1 of 2.
Goaltenders -- Princeton -- Ferland 16-10-4 (31 shots-29 saves). Union, Kupsky 11-11-2 (22-19).
T -- 2:20. A -- 2,000. Referees -- Joe Carusone, Marty Hughes. Linesmen -- Glen Cooke, Matt Brady.