Once again, Oklahoma State and Kansas State traded scores — and lot of them.

For the first time since 2006, the Cowboys didn't get the best of the Wildcats.

Kansas State quarterback Collin Klein piled up more than 300 yards of offense before leaving in the third quarter with an undisclosed injury, and third-ranked Kansas State remained unbeaten with a 44-30 victory over the Cowboys.

"They're a great team, and they made a lot of plays, but it came down to a couple possessions, and we turned the ball over, and you're not going to win like that," said Oklahoma State quarterback Clint Chelf, who took over when starter Wes Lunt left with his own injury in the third quarter. "We definitely had to play better than we did."

It was the first time since 2002 that the matchup was decided by more than 10 points.

Klein had thrown for 245 yards and run for 64 more before sneaking in for his 50th career rushing touchdown with 9:47 left in the third quarter. The Heisman Trophy front-runner didn't return to the field on the Wildcats' next offensive series.

Lunt left with an undisclosed injury after throwing his third interception in the third quarter. The freshman quarterback, who missed six weeks with a knee injury earlier this year, threw for 184 yards and a touchdown before giving way to Chelf.

By that point, the Wildcats (9-0, 6-0 Big 12) simply had to protect a 38-17 lead, which they built largely on the strength of five Oklahoma State turnovers.

And a 100-yard kickoff return by Tyler Lockett.

"That's as poorly as we've played on special teams — and obviously turned the ball over — in a long time," Oklahoma State coach Mike Gundy said. "Some of it is created by them. I'm not saying that they don't do a good job, but a lot of them were self-inflicted."

Allen Chapman picked off three passes and returned one 29 yards for a touchdown, and John Hubert had a pair of TD runs, keeping alive Kansas State's hopes of playing for a national title.

The Wildcats entered the weekend No. 2 in the BCS standings behind Alabama.

Chelf finished 16 of 27 for 233 yards and a touchdown for the Cowboys (5-3, 3-2), who should know something about playing late-season spoiler to a team in title contention. They were ranked No. 2 when they lost to Iowa State late last season, and got shut out of the BCS title game.

This one was just about as wild as last season's matchup in Stillwater, when the Cowboys held on in the final minutes after the teams combined for 32 fourth-quarter points.

Oklahoma State struck first when Lunt hit Austin Hays for a 54-yard touchdown reception, but the Wildcats came back with 17 straight points — Hubert's two touchdown runs were sandwiched around the first of Anthony Cantele's three field goals.

Quinn Sharp added the first of his three field goals to get the Cowboys within 17-10 before the fireworks really started: Lockett fielded the ensuing kickoff deep in his end zone and went the distance for his fourth career TD return, and Desmond Roland answered by fielding a short kickoff by Kansas State and going 80 yards for another touchdown return.

Chapman's pick-six made it 31-17 at halftime.

The Cowboys had the ball to start the second half, and Lunt appeared to get hurt while throwing an interception to Nigel Malone. He never returned to the game.

"Inexperience plays into it," Gundy said. "Obviously Wes didn't play very well at all. He threw a couple, three balls to them, and one of them for an interception. He's a freshman, so I would say inexperience had played a role there."

The Wildcats marched 93 yards before Klein's touchdown plunge from a yard out made it 38-17, the final play of his night. Daniel Sams went the rest of the way for Kansas State while Klein watched from the sideline without his helmet.

"Obviously he was injured or we wouldn't have taken him out," said Kansas State coach Bill Sndyer, who refused to discuss the nature or severity of the injury.

Sharp and Cantele traded field goals before Chelf hit Charlie Moore for a 13-yard touchdown catch to get the Cowboys within 41-27. The two kickers traded field goals again before Cantele missed from 24 yards to give Oklahoma State the ball with 4½ minutes left in the game.

The Cowboys marched to the Kansas State 8, but Chapman picked off Chelf in the end zone for his final interception of the night.

Though injuries at the quarterback position — Chelf had been the third-stringer behind Lunt and J.W. Walsh — throughout the season have been aggravating for Gundy, he said he was much more dismayed by the overall performance of the team.

"It's really more frustrating that we're turning the ball over," Gundy said. "Turning the ball over, playing poorly on special teams ... and not tackling well in the first half is more disturbing to me than the quarterback carousel in this game."