MANHATTAN, Kan. — Beating ranked teams on the road is something Iowa State has rarely done — this decade, last decade or any decade.

Before facing No. 5 Kansas State on Saturday as 15-point underdogs, the Cyclones were 7-104 away from home against ranked squads.

Now, thanks to the biggest upset in the Big 12's regular season, make that 8-104. Craig Brackins had 19 points before fouling out and Diante Garrett scored five in overtime, boosting the Cyclones to a stunning 85-82 victory over the cold-shooting and crestfallen Wildcats.

"It's a great win," said Greg McDermott, the Cyclones' fourth-year coach. "I hadn't beaten a ranked team in my time at Iowa State and people were kind enough to remind me of that often. So this is good to get that one over with."

Iowa State (15-16, 4-12 Big 12), the No. 11 seed in next week's Big 12 tournament, led almost the entire way until Denis Clemente hit a 3-pointer to forge a 74-all tie with a little more than a minute left.

But Garrett hit the first bucket in overtime and the Wildcats (24-6, 11-5), the No. 2 Big 12 seed, never caught up. Iowa State, which had lost seven of nine, got 18 points from Scott Christopherson and 13 from Marquis Gilstrap.

Christopherson iced the win with a pair of foul shots with 3.2 seconds to go, sending Kansas State into the postseason on a two-game losing streak. The Wildcats lost to No. 2 Kansas on Wednesday.

"They were switching up ball screens, so I had a mismatch with their bigs and I just took advantage of it," Garrett said. "This just gives us motivation to go into the tournament."

The Wildcats shot a miserable 34 percent, although Jacob Pullen had 27 points and Curtis Kelly 19.

"I thought we were real good at practice yesterday, but I think some of our inconsistencies during the course of the year kind of showed their ugly heads today," Kansas State coach Frank Martin said. "My hat's off to Greg McDermott. As disappointed as I am in our guys, I'm extremely happy for him, happy for those kids. With all the close losses they've had this year, (McDermott) continues to get those kids to play as hard as he does. I'm real happy for Greg."

The Wildcats, who won at Iowa State on Feb. 6, needed one victory to tie their best regular-season record ever. They entered the week hoping for a conference title and No. 1 seed in the NCAA tournament.

"We lost three home games," said Martin, who talked to his players for 35 minutes before emerging from the locker room. "That's who we are. We're not a championship-level team in the Big 12 because we can't win at home."

Clemente had 17 points for Kansas State on 5-of-18 shooting.

The Wildcats, who hadn't led since the score was in the mid-20s early in the first half, struggled all night with poor shooting and finished just 23 for 67. From the 3-point line, they were 3 for 23.

"I know why we won this game," Brackins said. "We were relentless. We didn't stop. We didn't let things get to us. I felt like we missed some free throws, but we nailed some when they were at the right time."

After Gilstrap's foul shot put Iowa State on top 83-79 in overtime, Pullen was fouled on a 3-point attempt and sank all three shots, making it 83-82. Christopherson's two foul shots clinched it for the Cyclones, who danced and hugged as Pullen's desperation 3-pointer missed from midcourt at the buzzer.

"This team has faced an unbelievable amount of adversity," McDermott said. "From injuries to defections to illnesses. And on top of that, there have been a lot of times we haven't gotten the bounce of the ball late in games, in close games. But today we made plays when we had to against a very good Kansas State team."

Justin Hamilton and LaRon Dendy each had 10 points for Iowa State.