Ole Miss (10-3) jumped out to a 34-6 lead by halftime, cruising up and down the field against an overwhelmed Oklahoma State defense. The onslaught was punctuated late in the second quarter when left tackle Laremy Tunsil had a 2-yard touchdown run on a trick play after a lateral from Kelly.
Oklahoma State (10-3) lost its final three games after 10 straight wins. The Cowboys fell into a 41-6 hole midway through the third quarter and never mounted a legitimate challenge.
Mason Rudolph was 18 of 31 for 179 yards for Oklahoma State. Ole Miss outgained Oklahoma State 554-366 in total yards.
Ole Miss was embarrassed a year ago in a 42-3 loss to TCU in the Peach Bowl and players vowed throughout the past month that the outcome would be much different.
They were right.
Ole Miss started off a little shaky after a couple early penalties helped Oklahoma State advance down the field. The Cowboys eventually kicked a short field goal for a 3-0 lead.
That was the end of the good news for the Cowboys, who were playing in the Sugar Bowl for the first time since 1946.
The Rebels' offense got on track later in the first quarter when Kelly hit a wide open Cody Core for a 31-yard touchdown that made it 10-3 and started the onslaught.
Treadwell added two touchdown catches in the first half and also completed a 45-yard pass after a lateral on a trick play. His second touchdown catch gave Ole Miss a 24-3 lead.
The Ole Miss fans -- who were cheering for the Rebels at the Sugar Bowl for the first time since 1970 -- were already in a frenzy when one more trick play by Freeze brought down the house.
With 5 seconds remaining in the second quarter, Kelly ran right and then fired back across his body to the 305-pound Tunsil, who caught the lateral and jogged into the end zone for a 2-yard rushing touchdown.
Ole Miss fans roared and the "S-E-C! S-E-C!" chant started in the Superdome: The Rebels had scored on their final six possessions of the first half and this one was essentially over.
Kelly's four touchdown passes and Treadwell's three touchdown catches tied Sugar Bowl records. Kelly completed 21 of 33 passes and ran for 73 yards on 10 carries.
For Oklahoma State, it was a rough ending to what started as a promising season. The Cowboys were in the middle of the playoff conversation in November after 10 straight wins, but losses to Baylor, Oklahoma and then Ole Miss exposed their defense. They gave up a combined 151 points in those three losses.
Follow David Brandt on Twitter: www.twitter.com/davidbrandtAP
AP College Football website: collegefootball.ap.org