Shane Ray returned a fumble 73 yards for a game-clinching score and No. 9 Missouri defeated No. 13 Oklahoma State, 41-31, in the matchup between former Big 12 rivals.
After Missouri's Henry Josey ran for a go-ahead 16-yard score with 3:08 left, Clint Chelf moved Oklahoma State to the Missouri 23 on the Cowboys' ensuing touch.
Faced with a 3rd-and-7, though, SEC Defensive Player of the Year Michael Sam fired off the ball and flew around tackle Chris Grisbhy before strip-sacking Chelf from behind.
Ray then scooped up the loose ball and went the other way to help SEC East- champion Missouri (12-2) match its school record for wins.
The triumph also gave head coach Gary Pinkel his school-record 102nd victory.
"What a game. Oklahoma State is a really good team. Just all the drama that you don't want as a coach in the fourth quarter we had. We had a lot of adversity. I thought our team handled the adversity very well. Fortunately we made the plays we needed to make to win it at the end," Pinkel said.
The SEC has won 10 of the last 11 Cotton Bowls.
Josey ran for 92 yards on 12 carries with three touchdowns, while James Franklin completed just 15-of-40 passes for 174 yards with an interception for the Tigers.
Chelf was 33-of-57 for 381 yards and a pair of touchdowns and interceptions for the Cowboys (10-3), who dropped back-to-back tilts to close the year.
"It's a tough way to lose the last two games. It's really hard on our team. I was proud of our effort. We had our chances," said Cowboys coach Mike Gundy.
Oklahoma State trailed 17-7 late in the third, but overcame the deficit by converting a pair of Franklin turnovers into 10 points in a 3 1/2 minute span.
Braylon Webb intercepted Chelf with 2:59 left in the period, Missouri gave OK State the ball right back when James Castleman pounced on a fumbled handoff exchange.
Chelf hit Jhajuan Seales for a 21-yard score three plays later.
Ryan Simmons recovered Franklin's second fumble early in the fourth and Ben Grogan booted through a 25-yard field goal to knot the tilt.
The field goal was the first of six straight possessions that the former conference foes traded points on.
Josey dashed through the middle for a 25-yard TD run on a 3rd-and-5 to again put Missouri in front, but Chelf broke off a 23-yard TD run to tie the game at 24-24 with 9:51 remaining.
Andrew Baggett split the uprights from 46 yards out to put Missouri back on top with 6:29 to play. A pass interference penalty negated Tyler Patmon's 40- yard interception return for a score earlier in the drive.
Chelf lofted a 41-yard completion to Tracy Moore along the left sideline on a 3rd-and-4 on the Cowboys' ensuing march before Desmond Roland bulled through the line and dragged a pair of Missouri defenders for a 2-yard TD run to give the Cowboys a 31-27 edge.
Josey's go-ahead TD run was preceded by Franklin's 27-yard completion to Dorial Green-Beckham on 3rd-and-9.
Earlier, Josey took an option pitch three yards for a touchdown to get Missouri on the board late in the opening frame before Chelf hit Josh Stewart for a 40-yard score on the Cowboys' next offensive sequence.
Missouri backup quarterback Maty Mauk threw a 24-yard TD pass to Marcus Lucas early in the second and Baggett split the uprights from 35 yards out on the final play of the half to give the Tigers a 17-7 advantage.
Missouri left the Big 12 two seasons ago ... Sam's sack gave him 11 1/2 on the season ... Oklahoma State attempted to win 11 games for the third time in the last four years ... Moore caught seven balls for 100 yards.