– It’s midnight, Cinderella.

Minnesota Duluth made that clear Saturday night and earned a trip to the NCAA Frozen Four in the process.

The Bulldogs beat Air Force 2-1 with a strong defensive performance in the West Regional final in front of 8,015 at the Denny Sanford Premier Center. A day earlier, the Falcons, the No. 16 overall seed in the NCAA men’s hockey tournament, eliminated top-seeded St. Cloud State.

With its victory, UMD advanced to the Frozen Four for the second consecutive year. The Bulldogs (23-16-3) will face the Midwest Regional champion, either Ohio State or Denver, in a semifinal on April 5 in St. Paul. Minnesota Duluth, the NCAA runner-up to Denver last year, won its only national title the last time the Frozen Four was at Xcel Energy Center, in 2011.

“We’re going home,’’ said Bulldogs sophomore defenseman Nick Wolff, whose first-period goal proved to be the winner. “We’ve all been there before, and it’s just great to be going home.’’

Air Force made it tense late, when Evan Giesler banked the puck off UMD goalie Hunter Shepard’s skate to trim the lead to 2-1 with 6 minutes, 16 seconds left in the third period. But the Bulldogs, who were the final at-large team to make the NCAA field, held on to win.

“The way we got in was a spark for our team,’’ said Bulldogs coach Scott Sandelin, whose team made the field when six conference tournament finals went UMD’s way last week to bump Minnesota. “It was dramatic, and our guys really appreciated the opportunity that they got.’’

Early on, it looked as if UMD was going to run Air Force (23-15-5) out of the building. Joey Anderson and Wolff scored 3:09 apart in the first period, and the Bulldogs held the Falcons to zero shots on goal in the period. In fact, Air Force didn’t register its first shot on goal until 23:55 had been played and was held to 12 total.

How lopsided was that first period? Air Force attempted only four shots, and all four were blocked.

“Duluth came out, and they took us to the woodshed in the first period in a big-time way,’’ Air Force coach Frank Serratore said. “We hadn’t seen speed like that all year.’’

In stunning St. Cloud State on Friday, Air Force took an early lead and rode the hot goaltending of Billy Christopoulos, who had allowed two goals total in his previous four games. The Bulldogs took that away, but the Falcons gained traction in the last 10 minutes of the second period. In the third, UMD controlled play for the most part but couldn’t add to its lead.

“They exerted a tremendous amount of energy trying to give us the knockout punch,’’ Serratore said, “and we took the punches, took the punches, took the punches, and we turned the game.’’

By hanging around, Air Force set up a frenetic finish with Giesler’s power-play goal. When the Bulldogs closed it out, their path to St. Paul was set.

“I’m really happy for guys like [captain] Karson Kuhlman and our seniors to have a shot at a national championship,’’ Sandelin said. “Most important, it’s exciting that it’s in St. Paul.

“We had a good memory there last time.’’