Gilder-Tilbury was 8 of 11 from the floor to help the Bobcats (4-2) shoot nearly 52 percent - despite the team going 2 of 9 from beyond the arc. Emani Gant had 13 points and Cameron Naylor added 10.
Texas-Rio Grande Valley (3-7) was led by J.J. Thompson with 18 points and five assists. Dakota Slaughter had 15 points and seven rebounds while Shaquille Hines added 14 points and eight boards.
Hines made a pair of free throws with 6:54 to go to pull the Vaqueros into a tie at 53. Gilder-Tilbury scored the next five points to start Texas State's 13-4 run to put it away.
Texas State had 12 steals as Texas-Rio Grande Valley turned it over 22 times.