Raivio sank four of six 3-point attempts and all six of his free throws as the Bulldogs (6-1) extended the nation's longest home winning streak to 43 games.
Keoni Watson and Mario Mackey led Idaho (1-4) with 11 points apiece. Watson hit just five of 17 shots and missed all five of his 3-point attempts. Mackey went 4-for-10, including 3-for-7 on 3-pointers.
Matt Bouldin hit a 3-pointer from the right corner at the buzzer to give Gonzaga a 43-28 lead at the half. The Vandals, much smaller and less experienced than the Bulldogs, never threatened in the second half.
Gonzaga shot a season-low 44.8 percent from the field, but held Idaho to 38.5 percent. The Bulldogs converted 18 of 23 free throws compared with 3 of 8 for Idaho.
Point guard Jeremy Pargo added 11 points, six assists, two steals and no turnovers in 33 minutes for Gonzaga.
Idaho has lost seven straight to Gonzaga, and 11 of the last 12 meetings. The Vandals still lead the all-time series, which dates back to 1909, 67-62.