Meanwhile, Landry Jones didn't keep up. Jones was good in the first half, not so good in the second half.
The Sooner running game didn't help. DeMarco Murray gained just 24 yards on 10 carries, though freshman Roy Finch showed he must play even more, with 59 yards on nine carries.
Jones threw for just 55 yards in the second half and misfired on all seven of his fourth-quarter throws.
This game was lost late third/early fourth quarter. The Sooner defense got a rare stop — Missouri never went three-plays-and-punt — and OU took at its 20-yard line, leading 21-20.
Finch gained a yard, then another on a swing pass, and finally Jones threw incomplete amid a heavy rush on the first play of the fourth quarter.
Gabbert took the Tigers on a five-play, 72-yard drive that never saw third down.
On OU's next play, Jones threw his second interception, both on low-risk passes, and this game was quickly slipping from the Sooners' grasp.
"We've been great all year taking care of the ball," OU offensive coordinator Kevin Wilson said.
Indeed, the Sooners entered with only five turnovers all year. But they committed three Saturday, two inside the Missouri 20-yard line.
"You can't win on the road doing that," Wilson said.
But Missouri lost two fumbles itself and allowed Mossis Madu's 77-yard kickoff return, which gave OU momentary life with six minutes left in the game.
So that's a near wash. It was the other stuff that killed the Sooners.
Missouri controlling the ball for 211/2 of the second half's 30 minutes. The Sooners making just seven first downs after halftime. Mizzou outgaining OU 287-101 in second-half yards.
That's what beat the Sooners. That's what knocked OU from the No. 1 perch that now can be somebody else's problem.
Berry Tramel: Berry can be reached at (405) 760-8080 or at firstname.lastname@example.org. He can be heard Monday through Friday from 4:40-5:20 p.m. on The Sports Animal radio network, including AM-640 and FM-98.1. You can also view his personality page at newsok.com/berrytramel.