The victory was the 200th in the coaching career of Oregon State coach Wayne Tinkle.
The Beavers, trying to bounce back from an injury-plagued 5-27 season and from the trauma of witnessing a terrorist attack while in Barcelona for a summer tour, got off to a great start after being picked to finish eighth in the Pac-12.
Tres Tinkle, the coach's son who was limited to six games (averaging 20.2 points and 8.3 rebounds) last year, is hoping to lead his team back from what he called the "big embarrassment" of last season.
So far, so good as he also grabbed six rebounds and went 8-for-11 from the floor.
The Thompson brothers, Ethan and Stephen Jr., played major roles -- Ethan with 20 points, eight rebounds and five assists in his college debut while Stephen recorded 16 points, six rebounds and three assists.
Drew Eubanks went 10 of 11 from the free-throw line and had 16 points and seven rebounds in the win.
The Beavers ran up a 44-33 rebounding advantage and shot 54 percent from the floor.
Jadon Cohee scored 21 points for the Thunderbirds of the Big Sky Conference, who went 6-27 last season.
Brandon Better scored 18 points, James McGee had 15 and Jacob Calloway 12 in the loss.