McKinney was 10 of 16 from the floor, including 5 of 7 from beyond the arc. Dylan Garrity added 18 points for Sacramento State (13-6, 7-1), which remains in first in the Big Sky by a half-game.
McKinney made a pair of free throws to tie the game at 37 at the half. Cody Demps' layup with 5:52 left gave the Hornets the lead for good as McKinney took over, scoring 13 points down the stretch - including three 3-pointers - to hold off Weber State.
Sacramento State shot 60 percent from the floor and was 10 of 17 on 3-point attempts.