The Nittany Lions recorded multiple hat tricks in its upset over the Terrapins.
Kristin O'Neill surpassed her single-season goal record as she led Penn State to a tight victory.
Northwestern's Izzy Scane scored six goals to reach her 60th of the season.
Despite a comeback effort, the Terrapins' five-goal lead in the second period proved to be too much to overcome.
The men's team sits at No. 10, while the women's team jumped to No. 20.
Gretchen Gilmore and Kristin O'Neill each scored six goals in the upset win for Penn State.