Niang went 4-for-5 from 3-point range while Elim put in 21 points and grabbed 12 rebounds for the unbeaten Cyclones (10-0), who advanced to the Wednesday championship game of the Diamond Head Classic.
Iowa State led 42-41 early in the second half when Niang's trey ignited a 19-4 run that sealed the outcome.
Dustin Hogue supplied 18 points with six rebounds and DeAndre Kane provided 15 and 11 for the Cyclones.
Reggie McAdams scored 13 points to pace the Zips (6-3).
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