Minnesota Duluth is the two-time defending NCAA men's hockey champion, and judging by a game that started Saturday night and stretched into Sunday morning, the Bulldogs are in no hurry to give up that title.

In the longest game in NCAA men's hockey tournament history, the Bulldogs defeated top-ranked North Dakota 3-2 in five overtimes in the Midwest Regional in Fargo. Luke Mylymok, a freshman who had played in only 10 games this season, scored 2:13 into the second overtime to give UMD (15-10-2) the victory over the Fighting Hawks (22-6-1) and their fourth consecutive trip to the Frozen Four.

The game lasted 142 minutes, 13 seconds of time on the ice. It began at 6:30 p.m. Central and ended at 12:42 when Mylymok's shot beat North Dakota goalie Adam Scheel and set off a Bulldogs celebration.

"I'm exhausted. It was an unbelievable game,'' Minnesota Duluth coach Scott Sandelin said. "I thought our team played great. North Dakota shows their resolve, ties it. And then we play a marathon overtime. … We got the fortunate break.''

The day was extra special for Sandelin, whose son, Ryan scored the winner in overtime in Minnesota State Mankato's 4-3 victory over Quinnipiac in the West Regional semifinals in Loveland, Colo.

Mylymok was just happy to be playing, let alone scoring the winner.

"When you get your name called and get to play in a game like this was unbelievable,'' he said.

After two scoreless periods to open the game, Minnesota Duluth took a 2-0 lead in the third period on goals by Jackson Cates 3:21 into the third period and Cole Koepke at 4:41.

North Dakota pulled Scheel for an extra attacker late in the game, and Colin Adams cut UMD's lead to 2-1 at 18:19. Then, Jordan Kawaguchi scored with 57 left in the period, also with Scheel pulled, to force overtime.

"Them getting those two late goals, our kids showed resolve after that,'' Sandelin said.

In the first overtime at 7:38, the Bulldogs appeared to score the game-winner when Koby Bender beat Scheel. A video review, however, ruled that UMD was offside entering the zone, so on to more over time the game went.

The Bulldogs replaced starting goalie Zach Stejskal with Ryan Fanti in the fourth overtime, presumably because of cramping. He finished with 57 saves on 59 shots. Fanti turned aside the six shots he faced. Scheel made 51 saves as UND outshot the Bulldogs 65-54.

"I couldn't be more proud of this group to just stick with it,'' Sandelin said. "They showed a little bit of a winning pedigree.''

In the Frozen Four semifinals, the Bulldogs will face East Regional champion Massachusetts in a rematch of the 2019 NCAA title game, which UMD won 3-0. Minnesota Duluth has played in three consecutive national championship games, falling 3-2 to Denver in 2017 in Chicago, beating Notre Dame 2-1 in 2018 in St. Paul and topping the Minutemen in Buffalo, N.Y., two years ago.

Minnesota Duluth's victory also guaranteed there will be at least two Minnesota teams in the Frozen Four. The winner of Sunday's West Regional final (7 p.m., ESPN2) between the Gophers and Minnesota State will make it, too. St. Cloud State can make it three from Minnesota in the Frozen Four if it beats Boston College in Sunday's Northeast Regional final (4:30 p.m., ESPN2).