The Vermont power play scored twice in 3:19 while the Colorado College unit went 0 for 7, and the Catamounts blanked the Tigers 3-0 in Burlington, Vermont, to start the 2017-18 campaign.
The Tigers almost escaped the first period, but the Catamounts' Ross Colton scored on the power play with 2.1 seconds left.
"We talked about it all preseason, not giving up goals in the final minute of a period," CC coach Mike Haviland told KRDO radio.
Vermont's Owen Grant widened the gap when he clanged his first career goal in off the crossbar 51 seconds into the second period.
The Tigers came out of a scrum a man down and Christian Evers made it 3-0 on the resulting power play 3:16 into the period.
"We worked on (the power play) all week, and we need to continue to work on it," Haviland said.
Colorado College couldn't respond on a 5-on-3 and Vermont's defense shut down the Tigers the rest of the way.
CC had the edge in shots, 33-27, but Vermont goaltender Stefanos Lekkas stood firm. The Tigers' Alex Leclerc made 24 saves as CC dropped its third straight opener against a Hockey East opponent.
The Tigers remain in Vermont and will seek their first goal of the regular season at 5 p.m. Saturday.