Alex Iafallo gives Minnesota Duluth the lead with 26.6 seconds left in the third period and the Bulldogs hold off a late charge by Harvard to win the Frozen Four semifinal matchup 2-1. (1:43)

CHICAGO -- When the clock ticked below one minute remaining in regulation with the score tied Thursday night, nerves were the furthest impulse from Minnesota-Duluth's collectively hardened exterior. The Bulldogs had not only been involved in tight, nail-bite-worthy hockey affairs this postseason -- they demonstrated each time how much they thrived under such pressure.

That experience and level-headedness revealed itself again on the biggest stage. Senior forward Alex Iafallo tipped in a shot from teammate Willie Raskob with 26.6 seconds left to lift Minnesota-Duluth to a thrilling 2-1 victory against Harvard in a Frozen Four semifinal at the United Center. The goal sneaked through the pads of Crimson goaltender Merrick Madsen, sparking a wild on-ice celebration, as teammates mobbed Iafallo by the boards. The Bulldogs then held off one last hard charge from Harvard, which nearly stole a goal late to extend the game to overtime.

Minnesota-Duluth advanced to the national championship game Saturday night (8 p.m. ET, ESPN) to face Denver, which defeated Notre Dame 6-1, in the second semifinal.

It was yet another magical moment for a Minnesota-Duluth team that has grown accustomed to flairs for the dramatic. Thursday's result marked the fourth consecutive postseason game in which the Bulldogs won in the final minute of regulation or in overtime. Minnesota-Duluth scored with 50.3 seconds left in the third period against North Dakota to secure an automatic bid to the NCAA tournament and followed up that performance with overtime victories against Ohio State and Boston University in the regional semifinal and final.

"I just think that we're a really composed team," said Bulldogs forward Joey Anderson, whose pass helped lead to the winning goal Thursday. "As the game wears on, we play a really good style that allows us to maintain our game, and we're able to finish chances when we get them. That's kind of been the way we've done it lately."

Minnesota-Duluth required every ounce of that composure Thursday night because Harvard almost equalized in stunning fashion following Iafallo's score. Harvard coach Ted Donato pulled Madsen to set up a 6-on-5 advantage for the last 26.6 seconds. Twice during that span, the Crimson hit the post amid a flurry of activity near Bulldogs goaltender Hunter Miska. Harvard senior Luke Esposito provided the best chance from straight on, but his shot smacked off the crossbar with four seconds remaining before Minnesota-Duluth cleared the puck for the victory.

"Obviously, it was heartbreaking when they scored that goal with 26 seconds," said Crimson forward Alexander Kerfoot, who held back tears afterward. "Everything just happened so fast. We had opportunities to score there at the end. Hit a couple posts. We took it to them. It just wasn't meant to be."

Alex Iafallo scores the winner for Minnesota-Duluth past Harvard goalie Merrick Madsen. Jonathan Daniel/Getty Images

Harvard opened well by taking advantage of a power play. Senior Tyler Moy scored at the 15:00 mark of the first period off Kerfoot's pass across the net to give the Crimson a 1-0 lead. But Minnesota-Duluth responded just over three minutes later when Andersen tied the score. The teams remained locked in a 1-1 draw for more than 30 minutes of ice time before Iafallo continued his torrid scoring pace. He now has scored or assisted on a goal in the Bulldogs' past 14 games, which began Feb. 4 against Omaha. Arguably none were bigger than his shot that settled into the net Thursday.

"It was a good pass by Joey," Iafallo said. "We kept it in there at the blue line. And that was pretty much the key to the goal. And Raskob made a good play. We do it in practice all the time. So simple things like that, getting the puck to the net. Just had to shovel it in."

The game did not go by without a bit of controversy. Harvard saw a potential go-ahead goal from Sean Malone negated at the 5:41 mark of the third period because a referee blew the play dead. Referees required a lengthy replay review before determining the goal did not count.

"The explanation I was given was that there was no audio on the replay," Donato said. "He thought the goalie at one point had it underneath his glove and in his mind, that's when the play was over. ... Obviously through my Harvard-colored glasses, it looked like a good goal. Everybody's trying to do their best out there."

Minnesota-Duluth ended Harvard's 18-game unbeaten streak, which represented the longest for a team participating in the Frozen Four since Northern Michigan in 1991. Harvard entered the night leading the country in scoring offense at 4.14 goals per game. But goals were difficult to come by in a physical contest, even as the Crimson took 40 shots -- the most surrendered by Minnesota-Duluth in regulation all season.

"Pretty much every bit of ice was hard to get out there," Donato said. "I don't think the game ever got probably up and down the ice as much as we would've liked."

Harvard closed its season 28-6-2 after reaching its first Frozen Four since 1994. Minnesota-Duluth (28-6-7) marched on to the title game, which it last won in 2011.

The Bulldogs can thank their breathtaking late-game heroics once more.

"Fortunately, we made a play at the end," Minnesota-Duluth coach Scott Sandelin said, "and got a little puck luck."