SMU opened the game with a 9-0 run and held a 21-point lead at the break, 40-19.
Sam Houston State held returning American Athletic Conference Player of the Year Nic Moore to just 8 points, but Ben Moore scored 15 points and grabbed eight rebounds and Keith Frazier added 13 points.
SMU shot 63.3 percent from the field (31 of 49) and 7 of 14 from beyond the arc.
The Bearkats were just 17 of 61 from the field (27.9 percent) and 6 of 27 from long range (22.2 percent).
Dakarai Henderson scored 17 points to lead Sam Houston State.
SMU enters the season after posting back-to-back 27-win seasons and winning the AAC regular season and tournament titles a year ago.