It seemed too good to be true.

The ISU football team was shutting out 16th-ranked Kansas at halftime, 20-0, on Saturday and would receive the ball to start in the third quarter.

From there on out, however, Iowa State’s upset bid unraveled as the lead quickly disappeared. Kansas scored on five of its six possessions to start the second half, and a late Iowa State comeback fell short in a 35-33 loss.

“I never felt the lead was safe. Ever,” coach Gene Chizik said. “Not against them. They’re too good on offense. We said that at halftime. I mean they weren’t going to lay down and roll over for Iowa State … If you’ve got a chance to beat ‘em when you’re up 20-0, you’ve got to put [them] to sleep, and we didn’t do it.”

As a result, the Cyclones suffered their third consecutive close loss, leaving the team and the home crowd with only disappointment and thoughts of, “What if?”

Iowa State (2-3, 0-1 Big 12) came out of the gates quickly, scoring touchdowns on its first two possessions and stymieing the vaunted Kansas offense.

The Jayhawks (4-1, 1-0 Big 12) came into the game averaging just over 35 points and 473 yards a contest but gained only 93 yards of total offense in the first half — 44 of which came on the final drive of the second quarter.

Kansas also turned the ball over three times in the first half but swung the momentum in its favor on its second offensive play of the third quarter.

The Jayhawks lined up in a shotgun set with three wide receivers and two running backs in the backfield, including junior Jake Sharp.

Sharp slipped out of the backfield on the passing play and ran uncovered down the sideline. He received a pass from quarterback Todd Reesing near midfield and ran into the end zone untouched for a 67-yard score.

Chizik said that play initiated the “snowball effect.”

Over the course of the second half, the Kansas offense made several clutch plays to pull away. On a fourth-and-7, Reesing laid a 23-yard touchdown pass over the shoulder of wide receiver Kerry Meier to tie game at 20. It was the second fourth down conversion on the drive for Kansas.

Kansas took a 21-20 lead by the end of the third quarter and stretched its lead to 35-26 with 3:39 left in the fourth.

Meanwhile, Iowa State sputtered on offense and converted just one of 11 on third downs until its final touchdown drive. On four of their first five drives of the second half, the Cyclones failed to gain third down yardage of four yards or less.

“We had a couple times where we really shoulda been able to get some yards and make some big plays at critical times in the game when everything was on the line,” Chizik said. “And we just didn’t get it done.”

Iowa State scored a touchdown with 1:15 left in the game and recovered an onside kick to give themselves a chance to win. Two dropped passes doomed the final drive, which Chizik described as “abysmal.”

“The bottom line is everybody talks about playing 60 minutes, and we haven’t done that yet,” Chizik said. “That’s really disappointing to me. We haven’t played a 60-minute game. We played 30 minutes and then we took a quarter off, and we tried to rally there in the end, and it was too late.”

Chizik said the Cyclones lost their sense of urgency in the second half and Kansas played with more energy. Senior Kurtis Taylor echoed that thought after the game.

“[Kansas] made their adjustments, but the bottom line is we didn’t come out with the same intensity,” Taylor said. “We didn’t come out with the same emotion that we had in that first half. That’s what we have got to maintain.”

ISU sophomore quarterback Austen Arnaud set career highs with 27 completions, 45 passing attempts, 268 yards passing and three touchdowns. He also fumbled and threw an interception but played the entirety of the game.

“If you look at the games we played, there’s an argument for us to be 5-0, where we just didn’t finish games,” Arnaud said. “We didn’t execute like we should have, and when it came down to the end in the past three games, we haven’t executed, and this loss hurts a lot to Iowa State and I’m sure the Iowa State faithful.”

Iowa State hasn’t beaten a ranked team since beating No. 22 Colorado, 30-16, on Nov. 12, 2005.

The 20-point comeback was the third largest in KU school history. Kansas’ largest rally was from 26 points down at Iowa State in 1992.