STILLWATER, Okla. – No. 25 Kansas State saw early momentum from a Malik Knowles’ 99-yard kickoff-return touchdown flattened by Oklahoma State quarterback Spencer Sanders and a Cowboys’ first-half scoring flurry, and the Wildcats saw their perfect start to the season end during a 31-20 loss Saturday night at Boone Pickens Stadium.

“Today they got us,” K-State head coach Chris Klieman said. “We’ve got to go back to work. It’s a long season, and we have an awful lot of opportunities in front of us. If we learn from this and continue to improve, we have a chance to be OK. Adversity has struck us for the first time this year and that’s reality. Now how do we respond when adversity strikes?

“I’m confident the leadership of our guys will respond to adversity.”

K-State was without sixth-year senior quarterback Skylar Thompson for a second-straight game. Thompson, who led K-State to a 45-40 upset win at No. 10 Oklahoma State in 2017, injured his right leg early in the game against Southern Illinois on September 11, and continues to rehabilitate with an uncertain timeline for his return.

“He can throw it, but we’ve got to make sure he can run it before he can play,” Klieman said, “and I don’t know if that’s two weeks, the open week, three weeks. We’ll keep progressing him.”

K-State’s bid to remain undefeated after four games for the first time since 2012 effectively came to a halt shortly after Knowles’ magical kickoff return with 6 minutes, 18 seconds left in the first quarter offered promise. Knowles fielded the kickoff down the right side at the 1, weaved past three defenders off blocks, stiff-armed another defender as he hit the middle of the field, then adjusted and angled back to the right side the final 50 yards into the end zone and a 10-7 lead.

K-State’s 123 non-offensive touchdowns since 1999 are the most in the nation, as are its 56 combined kickoff- and punt-return touchdowns since 2005.

Unfortunately for K-State, their cheers on the sideline didn’t last too long.

K-State, 3-1 overall and 0-1 in the Big 12, hadn’t allowed an opponent to score 24 points this season.

Oklahoma State put up 24 unanswered points in less than 18 minutes.

The Wildcats trailed 31-13 at halftime and couldn’t scratch back within single digits the rest of the way.

Oklahoma State, 4-0 and 1-0, entered 98th in scoring offense and with some apparent questions after the Cowboys fought off their first three opponents in Missouri State (23-16), Tulsa (28-23) and at Boise State (21-10) without scoring 30 points in any game. However, the Cowboys exploded with their best showing of the season, as the Wildcats were unable to solve Sanders and Jaylen Warren, who nearly had both 100 rushing yards and 100 receiving yards despite missing some time in the second half due to injury.

Sanders threw for two touchdowns and ran for another, as the Cowboys scored on drives of 75, 73 and 90 yards. Sanders completed 22 of 34 for 344 yards and two touchdowns to go along with nine carries for 18 yards and one touchdown. Warren had 27 carries for 123 yards and added four catches for 81 yards. Senior wide receiver Tay Martin had a game-high nine catches for 100 yards and one score.

“In the beginning, they got (Sanders) going and that’s what we couldn’t have, is Sanders getting some life and getting some confidence,” Klieman said. “When he did, he was really tough.”

K-State used both of its quarterbacks. Sophomore quarterback Jared Lewis came off the sideline to complete 10 of 19 passes for 148 yards with one touchdown and one interception after starter Will Howard suffered an injury. Howard, in his first career start in a full-capacity road environment, went 4 of 12 for 50 yards and had three carries for a team-high 28 yards. However, Howard also suffered one costly lost fumble late in the first quarter that resulted in a touchdown and the Wildcats trailed 21-10.

“(Howard) got hurt in the first half and couldn’t go anymore in the first half and then at halftime they did some things to work on him and he tried to go in the second half,” Klieman said, “but he couldn’t run the way he needed to run.”

Oklahoma State clamped down on Deuce Vaughn’s rushing game, holding the Wildcats’ biggest offensive weapon to season lows with just 22 yards on 13 carries. But Vaughn led the Wildcats with five catches for 73 yards and scored the only touchdown by the offense in the game.

“We couldn’t capitalize and couldn’t get anything going offensively other than the big play to Deuce,” Klieman said. “It was a frustrating night offensively.”

Oklahoma State outgained K-State 486-260 in total yards. K-State managed just 198 passing yards and a season-low 62 yards on the ground. K-State ranked sixth nationally in rushing defense in allowing less than 55 rushing yards per game, but Oklahoma State amassed 132.

As for exactly what happened to K-State’s defense?

“That’s a good question,” Klieman said. “We couldn’t tackle, and we couldn’t get off blocks. (Warren) is a good player, there’s no doubt about that, but we were a step slow, we couldn’t get our footing, and we couldn’t slow the game down enough, whatever you want to say, and we just couldn’t get a stop.”

The Wildcats suffered their seventh loss in their last eight trips to Stillwater while also opening a Big 12 Conference season away from home for the 21st time in the 26-year history of the league.

The Wildcats’ troubles began late in the first quarter when Oklahoma State struck with quick back-to-back scores. First, Sanders hit Brenan Presley with a 20-yard scoring toss. Then just 11 seconds later, linebacker Malcolm Rodriguez dived on the loose ball in the end zone following Howard’s fumble for another score.

“Bottom line, we can’t give them a free seven points, because we’re chasing those seven points the whole night,” Klieman said. “If it’s 24-20, maybe it’s not a different game, but maybe we have a better opportunity with some late drives.”

K-State went to Lewis on its first drive of the second quarter, but the Wildcats had to punt, and then suffered an interception on their next drive. Moments later, K-State’s defense, which entered the game ranked 23rd in total yards allowed, lost its best defensive player when linebacker Daniel Green was disqualified for targeting.

The Wildcats went the first half without an offensive score and Taiten Winkel drilled a career-long 45-yard field goal as time expired in the first half.

The second half featured no scoring spree from either team.

K-State’s offense finally hit the scoreboard with 1:08 left in the third quarter when Lewis’ gutsy improvision led to a long touchdown. Facing first-and-10 at the K-State 45-yard line, Lewis rolled to his right against intense pressure and completed a 4-yard pass to Vaughn across the middle of the field. Vaughn turned and darted 55 yards down the right sideline and into the end zone.

However, K-State was unable to further tighten the 31-20 gap. The Wildcats went 3-and-out on their next three possessions and could only watch Oklahoma State melt the clock while pondering their resolve as they head toward another big test.

The Wildcats host No. 4 Oklahoma on Saturday in Manhattan.

“This is a wide-open league and if you play really well you have an opportunity to win and if you don’t play well, you’re not going to win,” Klieman said. “Today, we got behind 31-10 and clawed our way back a little bit, but you can’t get down that much in this league.”