The Tigers evened their season mark at 3-3 as Markisha Patterson scored 16 points and Rachele Dobbins added 15.
Bearkat forward Britni Martin led all scorers with 18 points as Sam Houston dropped to 3-3 for the season. Angela Beadle added 12 points.
"It was a very physical game," Sam Houston head coach Brenda Nichols said. "We didn't do a good job of boxing out and rebounding and didn't put the ball in the basket when we needed to."
The game was tied five times with 13 lead changes. Sam Houston led by as many as seven points in the first half, but Grambling rallied to knot the game 26-26 at intermission.
The Tigers out-scored the Kats 38-26 in the second half.
Sam Houston hit 17-of-55 field goal attempts, going two of eight from three point range. Grambling out-rebounded the Bearkats 36-31 and shot 36 percent, hit 21-of-57 shots.
The Bearkat women will take a week off for finals.