Tiffany Thompson made 10 saves in the first period before being replaced by fellow junior Valery Turcotte, who made 21 saves in the final two periods.
Christine Jefferson put the Warriors on the board with an unassisted goal, and Sam Poyton added a pair of goals with some assistance from Lindsay DiPietro and Tegan Schroeder.
The Lakers again retaliated with three straight goals before Ashley King scored halfway through the third period and cut the Warriors' deficit to one. DiPietro and Emily Berzins earned assists on King's goal.
But Valerie Chouinard, an offensive threat all weekend for the Warriors, scored to put the Lakers ahead 7-5, the score that stood until the final horn.
The Lakers again significantly outshot the Warriors--this time 40-18--but the five Warrior goals were the most Mercyhurst had given up in nearly two years.
The Warriors (8-14-0, 1-3-0 CHA) begin a long road trip this weekend, when they face Quinnipiac.