COLUMBIA, Mo. (AP) -- 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 victory on Saturday 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 on a pass intended for Jeremy Maclin was the clincher.
"It was a great opportunity on a national stage," said Oklahoma State linebacker Andre Sexton, whose interception and 39-yard return set up a score that put the Cowboys ahead 28-17 in the fourth quarter. "We got a chance, and we just wanted to go out there and show everybody."
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 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 a 105 points per game. From the start it failed to live up to expectations for 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."
Missouri trailed only once in its previous five games, and then only briefly in the opener against Illinois. Oklahoma State grabbed the lead three times to stun a sellout crowd 68,349, going ahead for good on Davis' 40-yard reception for a 21-17 lead late in the third quarter.
Daniel, who entered with 15 touchdown passes and only one interception, pulled Missouri to 28-23 with 7-yard touchdown pass to Danario Alexander with 4:27 to go. Missouri got the ball at its own 35 after a shanked 10-yard punt with 2:40 to go.
But Daniel forced a throw into tight coverage and Lavine made the diving pick to wrap it up.
"They had some big playmakers, but we felt we had some big playmakers on our defense," Lavine said. "We knew the ball was going to Maclin. I tried to play him hard, and it worked out for me."
Missouri overcame several problems to take a 10-7 halftime lead.
Besides trailing for the second time all season, the Tigers went three-and-out on offense for the first time all year. Plus, their run of scoring a touchdown on their opening drive in every game ended when they stalled inside the 1 and settled for a chip shot field goal by Jeff Wolfert.
Wolfert broke Brad Smith's career scoring record on the opening drive, but missed two other kicks including one that was partially blocked.
Robinson scored on a 6-yard run on Oklahoma State's opening possession for a 7-3 lead. But the Cowboys' Dan Bailey missed a 25-yard field goal attempt early in the second quarter on a kick that may have been tipped.
(Copyright 2008 by The Associated Press. All Rights Reserved.)