"We made some big plays," Ford said. "We've had a lot of teams make some big plays on us this year late in games, and we came up on the short end. I thought tonight, we were on the positive end of that stick and made some plays."
After Smart's decisive bucket, Nash burned the Cowboys' last foul to give, and McGee was out of bounds when he caught another inbounds pass from Babb on a similar play. Hoiberg argued that McGee had been forced out, to no avail.
Babb ended up with a season-high 19 points to lead Iowa State, Niang added 16 points and Clyburn scored 14. Iowa State hasn't won at Gallagher-Iba Arena since 1988, losing 18 straight.
The last two have been decided right at the end, with Nash hitting a tiebreaking fadeaway jumper with 4.7 seconds left to lift Oklahoma State to a 69-67 win last season. That provided a measure of revenge for last season's first game at Hilton Coliseum, when Scott Christopherson banked in a 3-pointer at the buzzer for a 71-68 Iowa State win.
"It's been three tough ones since I've been here. We lost in overtime, last year's ending didn't turn out well, and then Smart ended it tonight," Hoiberg said. "It's a tough place to play."
Oklahoma State erased an 11-point deficit in the second half to turn it into a nail-biter, with 10 lead changes over a 6-minute stretch in the second half. Korie Lucious' driving layup with 2:16 to play put Iowa State up 76-72.
The Cowboys scored the next four points from the foul line to tie it, then got a chance to go ahead after Clyburn's drive against Nash came up empty with 30 seconds left.
Oklahoma State's Phil Forte chipped in 17 points, including three free throws in the final 2 minutes — two of them after Ejim blocked his shot and then slammed into him on the way back down.
The Cyclones were shooting 65 percent after making their first four shots of the second half to take a 50-39 lead after Ejim's hook shot in the lane with 17:19 to play.
Forte sparked Oklahoma State's comeback with a pair of 3s, and the Cowboys regained the lead at 54-53 when Nash completed a 10-0 run with a pair of free throws with 12:10 remaining.
Brian Williams made his season debut for the Cowboys after missing the first 18 games following surgery on his left wrist. Oklahoma State is almost back to full strength after a series of early-season injuries.
"This team has been through a lot of adversity and that's when that comes in, that experience from that helps you become stronger, and you just fight through it," Smart said. "That's kind of what we did tonight,"