But Hield couldn't keep the magic going. His fall-away jumper missed the mark, Clark was called for a foul with 1:58 to play and the Cyclones started extending the lead again.
Niang delivered the dagger, hitting his third 3-pointer of the game with just less than a minute remaining to all but end it.
Isaiah Cousins had 13 points and 10 rebounds and Woodard had 10 points — all after halftime. Spangler finished with 12 rebounds as the Sooners outrebounded Iowa State 46-33.
Oklahoma had 14 offensive rebounds but just four second-chance points. The Cyclones converted six offensive rebounds into eight points.
“Always when you get an offensive board, you'd like to finish it with a bucket,” Kruger said. “I thought throughout the game we had some opportunities that we didn't finish. We just have to slow down just a little bit and finish some opportunities that are there and be a little more efficient.”
Clark had seven points for the second consecutive game after scoring in double figures for 16 of the first 20 games.