COLUMBIA, Mo. — Chase Daniel's Heisman Trophy stock just plummeted. Missouri's national championship hopes took a tumble, too.

And how about them Oklahoma State Cowboys?

No. 17 Oklahoma State stopped an offense that had been scoring at will, intercepting Daniel's passes three times in the second half and upsetting the third-ranked Tigers, 28-23, last night.

"Put it all on me," Daniel said. "I should have made all three of those throws. It seemed like we were a little bit off all night. For the reason, I have no idea."

Zac Robinson and Damian Davis hooked up on a pair of long scores in the second half, and Patrick Lavine's interception at the Oklahoma State 31 with 1:41 to go was the clincher. Missouri (5-1, 1-1 Big 12) had appeared poised to challenge for No. 1 with a strong effort after top-ranked Oklahoma lost to Texas and No. 2 Alabama had the weekend off.

Instead of possibly being No. 1, Daniel expects Missouri will be playing against No. 1 next week at Texas.

"They'll probably be ranked No. 1," Daniel said. "It'll be a tough game, a lot of people there, and we've got to get going."

Even if Texas does get to No. 1, a win next week would shoot Missouri right back into the thick of the national title mix, but the Cowboys left the Tigers with little room for another slip up.

As for the Cowboys (6-0, 2-0), they're 6-0 for the first time since 1945 after going 18-19 in coach Mike Gundy's first three seasons.

"They're going to be at least No. 2 if they win," Gundy said of the Tigers. "I'm just really happy for our team. They put in a lot of hard work and effort, and they deserve it."

And it was Robinson, not Daniel, who played like a Heisman Trophy contender. Robinson was 19-for-28 for 215 yards and two touchdowns. Kendall Hunter had 154 yards on 24 carries and a 68-yard scoring run.

Daniel was fourth in the Heisman voting last season and considered a front-runner for the award through the first month of this season. He put up some more big numbers, 39-for-52 for 390 yards and a touchdown against the Cowboys but the interceptions were critical.

Missouri had won 10 in a row and 18 of 19 at home, but were held 19 points below their scoring average. Derrick Washington, averaging 100 yards rushing per game, was held to 11 yards on eight carries with a 5-yard scoring run.

"Your guts feel like they just got torn out if you're a competitor," coach Gary Pinkel said. "We just haven't been in this situation for a while, and this is really difficult for our players.

"We'll get going."

The game matched the second- and third-leading scoring teams in the nation, together combining for 105 points per game. From the start it failed to live up to expectations for a scoring-fest. Missouri was held to a field goal on its opening drive after 11 plays and nearly six minutes. Oklahoma State chewed up nearly five minutes before Robinson's 6-yard scoring run on its first drive.

"We felt we would have to score with them," Gundy said. "Our defense kept playing well, so our game plan was pretty solid."