Smith dropped into coverage and went high in the air to intercept a Bo Wallace pass at midfield with 7:06 left in the game and the Tigers protecting a 27-22 lead.
Late in the third quarter with Auburn ahead 27-16, Ole Miss Coach Hugh Freeze went for a 4th-and-4 with a Wallace pass to Jeff Scott. Smith made a big hit on the receiver to stop him a yard short of a first down and turn the ball back over to the Tigers at the AU 49.
Smith recorded four tackles and added his first career interception he returned for four yards before getting down.
"Nobody told me to get down," Smith said. "All I saw were those big Ole Miss linemen and decided I better get down and not take a chance on fumbling.
"I was prepared from watching film," he added. "I was trying to make a play, be in the right spot and do my job. I knew that our offense still had to go out and execute. It felt good to make a play for the defense as a whole. Everybody has confidence in each other on the defense."
The Auburn defense came up big after two fourth-quarter fumbles put Ole Miss in position to get back into the game or take a lead. The Tigers finished with six sacks==two each by Carl Lawson, Gabe Wright and Dee Ford.
Smith said the win was big. "It means a lot to get a win over a Top 25 team because we are trying to win respect Auburn deserves. That's what it comes down to."
In other news and notes:
*Auburn linebacker Cassanova McKinzy returned to the Auburn sideline late third quarter with neck brace after suffering a injury in the second quarter when he was wrapping up Ole Miss ball carrier and collided with teammate Montravius Adams. McKinzy was placed on a board and driven to East Alabama Medical Center in Opelika. Adams injured a knee on the play and did not return to action.
Auburn Coach Gus Malzahn said Adams could have returned if necessary. Malzahn said it was good to see McKinzy cheering on the sideline because he was healthy enough to do so.
*Serving as captains for Auburn were Reese Dismukes and Chris Davis, who have been captains all five games with the exception of the LSU contest when Davis was injured and didn't play. Senior defensive end Dee Ford was a captain in Davis' place against LSU. Davis returned to the starting lineup against Ole Miss.
*Senior Nosa Eguae made his first start for Auburn at defensive tackle after starting two games at defensive end earlier this year. Eguae, who has 33 career starts at defensive end, is listed at 6-3 and 269 pounds, very small for a defensive tackle where his quickness is being counted on to come into play. He also played some defensive end against the Rebels, finishing with three tackles that included 1.5 for losses totaling one yard.
*With junior wide receiver Jaylon Denson sidelined for the remainder of the season following a knee injury against LSU, Brandon Fulse moved into the starting spot. At 6-4 and 263 pounds, Fulse may be the biggest starting wide receiver ever for Auburn. Walk-on Melvin Ray, a 6-3, 213 sophomore who played professional baseball out of high school before enrolling at Auburn was listed second on the depth chart behind Fulse, who shifted to wide out from tight end.
Falling down the depth chart was sophomore Ricardo Louis, who along with Sammie Coates, led Auburn with 11 receptions going into the Ole Miss contest. Fulse had one reception for five yards, Ray didn't have a catch and Louis' one reception was for minus two yards.
*Redshirt freshman offensive tackle Shon Coleman switched from No. 72 to No. 37 against Ole Miss. Coleman switched numbers in case he was used a blocker out of the backfield, but he didn't make an appearance against the Rebels.
*Auburn now leads the series with Ole Miss 28-10, including a 14-2 advantage at Jordan-Hare Stadium. Saturday's game with Ole Miss was the 200th October game at Jordan-Hare Stadium for the Tigers who are 299-156-18 in the month of October and 164-33-3 in games played in October at Jordan-Hare Stadium.
*Auburn's appearance on ESPNU Saturday was the 77th time for the Tigers to be on an ESPN network, the most for any school. With 74 appearances on ESPN, Miami joins Auburn as the only two programs with more than 70 games televised ESPN.