Dwight Powell added 10 points for the Cardinal (11-5, 2-2 Pac-12), who won their second straight and six of eight overall. Marcus Allen added 11.
Que Johnson scored 21 points to lead the Cougars (8-9, 1-4), who lost their fourth in five games. Royce Woolridge added 13 points.
The Cougars played without their leading scorer DaVonte Lacy, who missed his third straight game with a rib injury. He's missed five of the past six Washington State contests.
Stanford led by as many as 32 points in the second half.
Robbie Lemons hit consecutive 3-pointers for the Cardinal as part of a 13-2 run over the final 4:14 of the first half that snapped a 27-all tie. Chasson Randle hit a jumper at the buzzer to give Stanford a 41-29 halftime advantage.
Huestis was 0 of 7 from the floor in Stanford's victory at Oregon on Sunday. He showed up to play against the Cougars, sporting a new hairstyle and hitting 7 of 10 shots overall. Huestis, who averages 10.5 points a game, reached double figures for the first time in conference play.
Brown was 1 of 10 in Stanford's 81-72 loss to Oregon State and is 15 of 19 in the two games since.
Washington State shot over 44 percent from the field in the first half but was held to less than 30 percent in the second half, in which the Cougars scored 19 points.
Stanford received a season-high 28 points from its bench.