AMES, Iowa (AP) — When most people think of Oklahoma, they think of Blake Griffin. If freshman Willie Warren keeps playing like he did on Saturday, folks may soon realize the fourth-ranked Sooners have more than just Griffin to rely on.

Warren scored 29 points and Oklahoma closed the game on a 13-2 run to beat Iowa State 78-68 for its ninth straight win.

Griffin was his usual self, scoring 23 points and grabbing 15 rebounds to extend his streak of games with at least 20 points and 15 boards to four. But if it wasn't for Warren, the Sooners (21-1, 7-0 Big 12) probably would have suffered their first conference loss.

Warren was 5-of-10 from 3-point range and finished one point shy of his third 30-point game of the season.

"He's done a great job all year. He really takes a lot of pressure off us inside, and every big game we've needed him to step up for us and he has," Griffin said of Warren.

The Sooners led by as many as 11 points in the first half. But Iowa State — fresh off a loss to last-place Colorado — rallied to make quite a game of it.

Oklahoma fell behind 66-65 late in the second half, as Iowa State's Jamie Vanderbeken and Lucca Staiger buried consecutive 3s. That's when Warren and Griffin stepped up to stave off the upset-minded Cyclones.

Griffin threw down a dunk to give the Sooners the lead, and Warren followed with a basket to put Oklahoma up 69-66. Griffin then stuffed Iowa State's Justin Hamilton near the basket, leading to a critical 3 by Austin Johnson that gave the Sooners a 72-66 lead with 1:48 left.

Griffin dashed Iowa State’s hopes for an upset by hitting a long turnaround jumper as the shot clock expired to make it 74-68.

Though the Sooners let Iowa State (12-9, 1-5) shoot nearly 46 percent from the field, their defense held the Cyclones to just one field goal over the final five minutes.

“I thought we made some huge plays down the stretch,” Oklahoma coach Jeff Capel said. “I’m really proud of our guys for showing some character and toughness down the stretch and making some plays.”

Craig Brackins had 19 points and 10 rebounds and Diante Garrett had 17 points and 10 assists for Iowa State, which has lost 12 straight to ranked opponents dating to 2006.

Iowa State took a 36-33 lead, its first since early in the game, on a 3-pointer by Staiger to open the second half. Warren gave the lead back to Oklahoma on a nifty layup that made it 49-47, and Griffin pushed it to 55-51 with an inside basket.

The Cyclones wouldn’t go away though, as Garrett’s layup put Iowa State up 58-57. The Sooners then went up 65-60, as Warren hit a 3 and two free throws before finding Griffin for a layup, but the 3s by Vanderbeken and Staiger gave the Cyclones their final lead.

The thought of coming so close to knocking off the Sooners only to lose its fourth straight game stung Iowa State. But the Cyclones took solace in the fact that they put a major scare into one of the nation’s best teams.