ESPN's Fran Fraschilla and Brent Musburger discussed the plays that the Iowa State Cyclones made to fuel their 77-70 comeback win over Oklahoma. (1:46)

AMES, Iowa -- Oklahoma was up by 20 when Isaiah Cousins hollered at the Iowa State bench.

Cousins got a technical foul, and the Cyclones got all the motivation they needed to spark one of the best comebacks in school history.

Georges Niang had 20 of his 23 points in the second half, and No. 17 Iowa State rallied from a 21-point deficit to stun No. 15 Oklahoma 77-70 and snap a two-game losing streak on Monday.

Monte Morris had 19 points for the Cyclones (21-8, 11-6 Big 12), who maintained their slim shot at a share of the conference title with one of the wilder league games in years.

Oklahoma raced to a 19-point halftime lead, but Iowa State scored 22 straight points in just over five minutes -- all immediately following Cousins' technical -- and outscored the Sooners 59-33 in the second half.

"When someone gets up in your face and [is] telling you how they're kicking your butt, you're going to retaliate in some way," Niang said. "Luckily, we retaliated the right way. That was just the push that we needed."

Buddy Hield had 26 points for the Sooners (20-9, 11-6), who lost for just the second time in 10 games.

Oklahoma had survived scares in its previous three games, needing overtime to beat Texas Tech and rallying past Texas and TCU for narrow wins.

The Sooners looked as though they had the Cyclones buried by halftime.

Oklahoma dominated the offensive glass, forced Iowa State to turn it over 10 times in 15 minutes and jumped ahead 37-18. It was a stunning score, considering the Cyclones had won 21 straight home games before last week's loss to Baylor.

But Cousins was whistled following a block by teammate Ryan Spangler with Oklahoma ahead 48-28 -- and the Cyclones finally got going. Their furious run was capped by a 3-pointer from Dustin Hogue that put Iowa State ahead 50-48 with 9:33 left.

The Cyclones kept pushing, and Niang's 3 gave them a 59-52 lead with 6:43 left.

"What they did in the first half wasn't likely to happen in the second half. They responded well," Oklahoma coach Lon Kruger said. "We contributed to it, for sure."

Jameel McKay had 14 points and 12 rebounds for Iowa State, including 10 in the first half to keep the Cyclones within relative striking distance.

Morris, like Niang, took over in the second half and scored all but two of his points.

"I thought it was really a great mental half. We needed that. We needed that in a bad way. Obviously, it was a team that was struggling," Iowa State coach Fred Hoiberg said. "Hopefully, this is what we need to get our confidence back to the point where we can get some momentum going into the tournament."

TIP-INS:

Iowa State: The Cyclones have won at least 11 Big 12 games in each of the past four seasons. ... Long and McKay staged an impromptu 3-point shooting contest from behind the courtside seats. Long ended it with a swish.

Oklahoma: Cousins had 12 points ...The Sooners more than doubled up Iowa State by halftime, despite shooting just 38 percent. That's because Oklahoma, helped by a 6-1 edge on the offensive glass, had 10 more shots than the Cyclones.

STAT LINES

The rally matched the largest second-half comeback in school history (Western Illinois, 1999) and was, according to Iowa State, the largest by a major conference team in 2014-15.

QUOTABLE

"It just really looked like they were punking us in our own house on Senior Night, and we couldn't let that happen," Niang said.

UP NEXT

Iowa State plays at TCU on Saturday.

The Sooners host No. 9 Kansas on Saturday.