The Colonials fired at a .750 clip from the charity stripe, hitting crucial shots down the stretch.
The Explorers worked the lead to 14 points until the Colonials built up an 11-point run of their own in the waning minutes of the fourth quarter.
Despite trailing by 10 points early in the second quarter, the Colonials rallied the rest of the game and denied the Rams a last-second chance to steal the game.
The Billikens shoot 33.6 percent from deep on the season. But Saint Louis drained 56.3 percent of its attempts from beyond the arc on 9-of-16 shooting against GW.
A three-pointer with 1:06 on the clock from graduate student Ariel Stephenson lifted the Colonials over the Minutewomen in a back-and-forth fight Sunday.
The Flyers crashed the boards hard and outrebounded the Colonials 40-18.
Taiwo bolted into A-10 play, garnering a career-high 14 rebounds against Fordham and a career-high 18 points in a victory over Duquesne.
Graduate student forward Alexandra Maund notched a floor-leading and season-high 17 points and secured seven rebounds.
The Colonials coughed up a nine-point halftime lead and allowed William and Mary to net 21 points in the fourth quarter to complete the comeback.
GW netted nine points from deep but made up for the low point production with 32 points in the paint.