Penn State was outscored 9-2 after jumping out to an early 4-1 lead.
The Lady Bulldogs were the first team with an active winning record Penn State's played this year.
Katie DeSa was 24-for-24, shutting out Robert Morris.
Penn State roared back from an early three-goal deficit but ultimately fell short.
Kaitlyn MacBean's goal in the 46th minute proved the difference.
Four different Penn State skaters found the score sheet in a dominant victory.