The Blue Jays trailed 36-25 early in the second period but battled back. McDermott made a free throw with 30 seconds to go that put Creighton up 58-55. However, the Blue Jays wouldn't score again, missing three free throws down the stretch.
Alabama (21-12), having gotten to within 1 point when Andrew Steele converted a nice feed from JaMychal Green, had a chance to win with 2.4 seconds left. But Creighton played good defense and a desperation long try from Trevor Releford was well short.
Creighton (29-5) advances to a third-round game Sunday against Midwest Region No. 1-seed North Carolina, which beat 16th-seeded Vermont 77-58 Friday.
The Blue Jays erased the double-digit deficit with a pair of runs, including a 10-2 spurt that put Creighton up 51-50 with 5:40 go with McDermott converting a pass from Grant Gibbs.
McDermott had nine rebounds to go with his 16 points and Gibbs had 10 points, six rebounds and four assists.
Releford had a team-high 14 points for Alabama.