ST. PAUL, Minn. — Turns out, all the Denver Pioneers needed was about nine minutes.

Denver scored four goals in a span of 9 minutes, 9 seconds between the first and second periods in a 7-2 NCAA West Regional win over Boston University on Saturday at the Xcel Energy Center.

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Defenseman Will Butcher had two goals, including one early in the second that deflated BU and let the Pioneers cruise the rest of the way to a blowout victory and to a second straight regional final.

With 1:22 of power play to open the second, Butcher wasted little time, getting a clean look from the point and firing a wrist shot that beat goaltender Sean Maguire for a 3-0 Pioneers lead just 24 seconds into the frame.

“I thought that third goal, Butchy’s goal to start the second period, I thought was a huge momentum swing,” Denver coach Jim Montgomery said. “It kind of put a knife in them for a little while and allowed us to keep our momentum and play fast and stay in their end for the next probably six to eight minutes.”

Denver added two more in the period off rushes, with Matt Marcinew putting away a one-timer on a rush to chase Maguire and bring in Connor LaCouvee at the 2:58 mark of the second.

Denver added another on a rush after a nice feed across the ice in the neutral zone found Troy Terry, who pushed it up to Evan Janssen, who slid a backhander five-hole for a 5-0 lead at the 15:48 mark.

It was that third goal, however, that changed the feel of the game for the Terriers.

“They got an early power-play goal there, so it’s obviously tough,” BU captain Matt Grzelcyk said. “You could see guys, you could see their heads go down. We kind of lost belief right from the start there.”

DU noticed, and once it was 4-0 less than three minutes into the second, it felt like the Pioneers had the game in hand.

“You could see them hang their heads a little bit and then we just talked about, let’s go here, let’s put the foot on the gas pedal while they’re down,” Montgomery said.

Early on, however, Boston University was the aggressor. The Terriers had an early 7-2 shots on goal advantage in the first and earned a pair of power-play opportunities in the first 10 minutes of the game.

“First five to 10 minutes, I thought that BU was the better team,” Montgomery said. “I thought we were playing nervous. After that, I thought our penalty kill gave us a lot of momentum and we started managing the puck well and we started playing our game.”

The Terriers said they just haven’t been mentally tough enough since a loss at Notre Dame on the last night of the regular season in late February.

“I think we were obviously really proud of how we came out,” Grzelcyk said. “I thought we had a lot of energy for a team that didn’t have a game the last two weeks. We definitely felt good about going into the rest of the game. But ever since they got that first goal, it seemed like we never faced adversity before, which was definitely frustrating.”

Six different Pioneers players scored goals and 11 notched points. Both of BU’s goals came in the third period after it was already 6-0.

Blake Hillman scored his second of the season on a rebound, crashing the net on a rush after Maguire stopped an initial shot from Janssen at 13:49 of the first. Dylan Gambrell added to the lead on a backhander off a nice find from behind the net from Danton Heinen at the 17:40 mark to make it 2-0 after one period.

A five-minute major followed by another minor gave Denver a five-on-three power play early in he third, and Butcher scored his second of the game to make it 6-0.

Danny O’Regan scored BU’s first goal on a rebound at the 12:45 mark of the third. Trevor Moore added one for Denver less than two minutes later to make it 7-1, and Mike Moran got a tip-in for the Terriers’ final goal with 14.7 seconds to play.

That stretch of goals between the first and second periods, however, was enough for DU to seize control. A second period fueled by a strong Pioneers forecheck helped stymie BU’s offense and produce chances the other way.

“It was awesome to see us execute on a couple odd-man rushes and play good defensively,” Denver captain Grant Arnold said. “We were playing the body. It was a great game for us. I’m proud of our team.”

BU finished the season 21-13-5, while Denver moved to 24-9-6.

Denver meets WCHA champion Ferris State in the West Regional championship, seeking a first Frozen Four berth since 2005. The game is set for 4 p.m. CDT Sunday. The Bulldogs beat St. Cloud State 5-4 in overtime in the early semifinal.