Galloway hit two free throws to make it 70-67 after a flagrant foul on Bryon Allen. A basket by Galloway ended a 9-0 run as the Hawks took a 74-67 lead with 3:15 to go. Ndao hit two free throws with 59.8 seconds left to make it 78-70, and Galloway sealed the win with two free throws with 24.6 seconds left to make it 82-75.
George Mason (7-9, 0-2) was paced by Jalen Jenkins, who had 20 points.
In a fast-paced first half, with both teams getting off shots early on most possessions, Mason took a 45-40 lead into the break despite 10 points from Galloway. The Patriots made 7 of 14 three-pointers in the first half and led even though St. Joe's shot 60.9 percent in the first half.
Ronald Roberts Jr., a senior forward for the Hawks averaging 14.6 points per contest, missed most of the second half Wednesday in a loss at No. 19 UMass and did not make the trip to Mason due to back spasms. It was the first game he has not played after seeing action in the first 113 games of his college career.
Ndao got his first start of the season in place of Roberts, who started the first 14 games. St. Joe's sophomore forward Isaiah Miles did not play for the second straight game after he suffered a concussion Jan. 4 against Denver. He was with the team but did not dress.
George Mason, in its first-ever A-10 home game, had lost six of its last eight games. Mason reserve junior forward/center Erik Copes of Imhotep Charter had six points.
Next up for St. Joseph's is a home game Wednesday with Atlantic Ten foe Duquesne.