Elk River scored the first four goals and held off Armstrong-Cooper, a team higher in the standings, 4-2 at home on Friday evening.
Samantha Westgaard punctured the net in the first period, and the Elks had a big second period with Abby Canton, Breanna Simon, and Canton again scoring.
McKenna Wesloh assisted on two goals. Jenna Gerger, Kaylee Forster, and Chelsey Petrich all made one assist.
Elk goalie Jessica Edwards stopped 25 of 27 shots. Marissa Odell and Alyssa Burke scored against her.
The Elks improved to 3-6-2 in the conference and 5-9-3 overall. Armstrong-Cooper drops to 7-4 in conference and 11-6-1 overall.
The Elks will play at Blaine on Tuesday.