The game was physical for all 60 minutes, culminating in the second period with a fight between Ice Lions' Adam Quinones and Marist's Mike Librizzi.
There were four instances of 4-on-4 hockey and the two teams combined for a total of 11 power plays.
"The power play was very important for us," said assistant coach Pat Fung. "We didn't really do much in the second period so we were lucky we stayed up 3-0."
Penn State held advantages in shots and face-offs. Both statistics have been important for Penn State in winning games this season.
"I think if we play a complete game then we'll blow teams away," Adam Levine said.
Levine won many face-offs for the Lions and scored the Lions' second goal of the night. Chris Stoehr, Jordan Katz, Mike Marley and Jordan Hellman also scored for Penn State.
The Lions also beat No. 12 Montclair State (7-12-3), 10-0, on Friday night.
"We blew them out, [Montclair St. wasn't] even that bad," Koletsky said.
Penn State Ice Lions coach Mo Stroemel was not behind the bench for either game. He attended a conference in California and will return this week.