NORMAN, Okla. -- Oklahoma coach Lon Kruger had been searching for signs that his young, talented team was growing up.
It was a big step for the Sooners, who had lost two of three and were coming off a 90-83 home loss to Kansas on Wednesday. Oklahoma knew it could score, but good defense in key moments had been absent.
"In the second half there, we got two or three stops we really needed," Kruger said. "We've been trying to learn how to do that."
Isaiah Cousins added 17 points for the Sooners (13-3, 2-1 Big 12), who ended No. 9 Iowa State's school-best winning streak at 14 games.
Kruger said the win against Fred Hoiberg's Cyclones was important. Iowa State was off to its best start ever, and many times in the second half, the Cyclones made the kinds of runs that have won them games this season.
"Huge win, obviously," Kruger said. "Fred does such a good job. They've got so many weapons. They space the floor and just make it awfully tough to guard. You've got to pick your poison sometimes. I'm really happy for our guys."
Spangler, a 6-foot-8, 232-pound sophomore, constantly outhustled Iowa State's more athletic big men.
"Ryan just took over the game," Kruger said. "Did some great things offensively and rebounded the ball like crazy. The guy gets so much respect for how he approaches it because he brings it every day and doesn't care about anything else except the team."
The Sooners won despite a rough day for Cameron Clark. The Big 12's leading scorer finished with 12 points on 4-for-16 shooting. The Sooners were fine because they matched a season high with 13 3-pointers and outrebounded the Cyclones 41-34.
Iowa State's DeAndre Kane had 23 points and nine rebounds before going down with an ankle injury. He left the game with 22 seconds remaining.
"It looked like he was making a play to the basket and I'm assuming that he stepped on one of their players' feet," Hoiberg said. "I'm guessing that's how he turned it."
The stat that bothered the Cyclones the most: Oklahoma's 22-2 advantage in second-chance points.
"That's the game right there," Niang said.
Ejim's 3-pointer with 2:39 remaining gave Iowa State its first lead since early in the second half. Spangler came right back with an old-fashioned three-point play to give the Sooners a 79-77 lead.
"To get right back in the lead at that point -- I thought that was a huge possession," Kruger said.
After Oklahoma got a stop, Hield scored on a layup to bump the lead to four.
Ejim missed a putback dunk on the other end and OU rebounded. Cousins made two free throws with 57.9 seconds to play, pushing the Sooners' lead to six.
Hield missed a pair of free throws to leave an opening for the Cyclones, but they couldn't take advantage.
The teams were tied at 39 at halftime, but Oklahoma was hot out of the break. The Sooners hit four 3-pointers in the first six minutes, including three by Hield, to take a 56-46 lead.
After forcing an Iowa State turnover, Hield raised his arms to get the crowd going, Shortly after that, Cousins hit a three to push the lead to 13 and force an Iowa State timeout.
The Cyclones started to creep back into the game. Kane made a pair of free throws to cut Oklahoma's lead to 64-58 with 8:59 to play. Iowa State cut the lead to three, but Niang committed his fourth foul with 7:42 remaining.
Oklahoma regained control with the kind of intensity it demonstrated throughout the game. Spangler hustled for an offensive rebound, leading to a 3-pointer by Jordan Woodard that bumped the Sooners' lead back to 71-63.
A baseline dunk by Iowa State's Hogue trimmed Oklahoma's lead to 76-74 and set up the final three minutes.
That's when the growth Kruger has been searching for showed up.
"A lot of people can play when you've got the momentum and you're knocking down shots and things are going well," he said. "Now, Iowa State's got the momentum and we've got to check ourselves. Line up and go out and reclaim the lead. And I thought our guys did that."