However, it was then Northwestern's turn to make a run, as the Wildcats reeled off four straight goals, including two in the half's final two minutes.
In the second half, both teams battled back and forth as the game was tied on three separate occasions. But in the end, the Wildcats (10-1, 3-0) completed their comeback and beat Penn State (3-9, 1-2) 13-11 to remain undefeated in the American Lacrosse Conference (ALC).
"Obviously people are disappointed," midfielder Katie Hartman said. "All we can do is look ahead. We can't change what happened. There's still a long shot for us to make the tournament."
A long shot is right.
After losses to William & Mary, Virginia, Maryland and Loyola earlier this year, the Lions were disappointed, but because those games were not against ALC teams, they knew that they still had a chance to make a run for a spot in the NCAA tournament.
However, with the loss to Northwestern, Penn State is just 1-2 in the ALC while the Wildcats and Johns Hopkins are both undefeated. After one of its best starts of the season, turnovers and missed opportunities now will almost definitely leave Penn State on the outside looking in come tournament time.
"It was just a mental lapse," Penn State women's lacrosse coach Suzanne Isidor said.
"We started making mistakes, we didn't make in the beginning of the game. We definitely lost communication and offensively we turned the ball over."
Once the Wildcats were able to gain leads in the second half, they played smart, controlling the ball and not forcing any opportunities on offense. The win was Northwestern's ninth in a row. Still, Hartman said the loss could be chalked up to mistakes the Lions made after getting the five-goal lead.
"We knew coming into this game how big it was and how much it meant to the rest of our season," she said. "We came out really fired up. We just kind of got complacent and satisfied with the lead and they went on a run."
The team that Isidor called the most talented group she's coached at Penn State will likely have to find different motivation than the NCAA tournament as it plays out its final five games of the season.