Shenandoah (11-2, 5-0 ODAC) needed just 2:50 to score what proved to be the game-winning goal over the Wasps (3-9, 0-4).
It took less than three minutes for Yergin to strike again; senior Alysha McCleaf set up Yergin's 19th goal of the season at 5:44.
Jessica Stuart and Micayla Hellerstendt closed out the first half scoring with goals in the 21st and 45th minutes, respectively.
Cottoms closed the book on the day's scoring with goals at 80:03 and 84:56.
Shenandoah took all 37 of the game's shots and had a 4-1 advantage in corner kicks.
The Hornets continue this homestand on Wednesday with a 7 p.m. non-league contest against No. 14/RV Johns Hopkins.