The Bluejays overcame a 17-point, first-half deficit to remain unbeaten.
After Wragge gave Creighton an 84-81 advantage, Xavier Thames hit two foul shots for San Diego State.
Creighton's Jahenns Manigat was then fouled and he made his first free throw with 5.5 seconds remaining. His second attempt misfired, but he chased down the offensive rebound to clinch the victory.
The Bluejays (6-0), who battled back to trail by only four at halftime, was led by Doug McDermott with 25 points. Wragge added 19 while hitting 7-of-10 from the field.
Thames had 21 for San Diego State (7-2).
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