The Terps gave up the last five goals of the game after leading 14-10 with under ten minutes left.
The Terps will face James Madison on Sunday at 1 p.m.
Lamoureux has provided a much-needed consistency with her energy, outlook and reliability to a revamped Terps defense.
The Terps will play for their fifth Big Ten championship after outscoring the Scarlet Knights 10-1 in the first half.
The tool quickly became a daily fixture for Abby Bosco, Maryland’s defensive line leader, and Emily Sterling, the team’s goalie.
The Terps will face Rutgers Thursday for a spot in the Big Ten tournament championship.
The Terps scored just two second-half goals in Saturday's loss to the Wildcats.
The Terps were outscored 9-2 in the second half.
The Terps dropped their first Big Ten game of the season to the Nittany Lions.
The Terps won the draw control battle against the Buckeyes 19-10 on Saturday.