After Grand Canyon's DeWayne Russell missed a jump shot with 11 seconds left, Seattle's Isiah Umipig drove to the basket but had his layup blocked out of bounds by Woolridge. On the inbounds pass, Emerson Murray lost the ball amid a crowd under the basket to end the game.
Alexander led the Antelopes (13-11, 4-3 Western Athletic) with 18 points and seven rebounds. Ryan Majerle added 16 points and Woolridge 10.
Seattle led by nine in second half but a 10-O run gave Grand Canyon a 50-49 lead with 11:50 left and the game stayed tight till the end.