MANHATTAN, Kan. (AP) -- Collin Klein piled up more than 300 yards of offense before leaving in the third quarter with an undisclosed injury, and No. 3 Kansas State remained unbeaten with a 44-30 victory over Oklahoma State on Saturday night.
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.
Oklahoma State's Wes Lunt also left with an 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 Clint Chelf.
By that point, the Wildcats (9-0, 6-0 Big 12) simply had to protect a 38-17 lead.
Allen Chapman picked off three passes and returned one 29 yards for a touchdown, John Hubert had a pair of TD runs, and Tyler Lockett returned a kickoff 100 yards for another score as Kansas State kept alive its hopes of playing for a national championship.
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.
Oklahoma State was ranked No. 2 when it 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 unanswered 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 field 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.
The Wildcats marched 93 yards before Klein's touchdown plunge from a yard out made it 38-17, but he also left the game with an injury. Daniel Sams played the rest of the way for Kansas State while Klein watched from the sideline without his helmet.
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 4 1/2 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. The three picks were one shy of Jaime Mendez's school record set against Temple on Sept. 26, 1992.
Kansas State ran out the clock to end the Cowboys' three-game winning streak and lock up its first win over them since 2006. The Wildcats have scored at least 44 points six times this season, and this time did it against a team that had allowed 38 total over its last three games.