Auburn scored two runs in the 13th and had two runners on base when Corley struck out designated hitter Josh Bell to end the four-hour, five-minute marathon.
Brett Cleveland (2-0), the fourth of five Bulldog pitchers in the game, earned the win with three innings of shutout relief. With the score tied at 6-6, Cleveland entered the game in the 10th, retiring two batters on two pitches. He then worked around a one-out double in the 11th and a lead-off fielding miscue and a walk in the 12th.
Cory Dueitt (3-4), Auburn's fourth pitcher, worked the 13th for the Tigers. Brian LaNinfa greeted Dueitt with an inning-opening triple into the left-center field gap. Dueitt issued a one-out walk to Jeff Butts and intentionally walked Jeffrey Rea to load the bases. That set the stage for Gendron's third hit of the game, a gapper to right.
Gendron paced MSU's 14-hit attack with three hits and his first three-RBI game of the year.
LaNinfa, Craig Tatum and Rea had two-hit outings. Auburn totaled 16 hits and got a 5-for-7 plate performance from Tug Hulett and a three-hit effort from Clete Thomas.
Auburn scored an unearned run in the first inning to claim an early lead off Bulldog starter Todd Doolittle. Sean Gamble reached on second baseman Jeffrey Rea's throwing error. Gamble advanced a base and scored on consecutive singles by Tug Hulett and Clete Thomas.
The Bulldogs jumped on Auburn starter Arnold Hughey for three runs during a four-hit fourth-inning burst. Craig Tatum opened the frame with a single to left. Brad Jones and Thomas Berkery beat out bunt singles, and Tyler Scarbrough then punched a two-strike single through the right side of the infield, scoring Tatum and Jones. Berkery advanced to third on a sacrifice bunt by Joseph Hunter and scored on Jeff Butts' sacrifice fly to center field.
Auburn answered in the bottom of the fourth with a solo home run to left by Derek Sain, his second home run of the season.
The Tigers regained the lead in their next at-bat, plating four runs on five hits and a pair of Bulldog errors. Ben Sprague opened the inning with a single and advanced to third on a muffed double play attempt. Chuck Jeroloman's single to left scored Sprague and ended Doolittle's stay in the game. Auburn greeted Doolittle's replacement, lefty Brooks Dunn, with three straight singles by Hulett, Thomas and Josh Bell.
State chipped away with single runs in the sixth, seventh and eighth innings.
In the sixth, Brad Jones scored on Joseph Hunter's infield groundout after being struck by a pitch.
Jeffrey Rea extended his hitting streak to 13 games with a lead-off single in the seventh, advanced on a Steve Gendron single to right and a Brad Corley grroundout and then came home on a wild pitch by Hughey.
State pulled even in the eighth when Butts singled through the right side, stole second and came home on Rea's single up the middle. LaNinfa, who opened MSU's 13th inning rally with a triple, delivered a pinch-hit single in the eighth but was later thrown out at the plate.
Rea wasn't the only Bulldog thrown out. MSU skipper Ron polk, who picked up his 400th career SEC win and his 990th win in 25 seasons at State, was ejected in the fifth inning following an argument with first base umpire Rick Darby about a call on a double play attempt by the Bulldog infield.
"I thought we had (the runner) beat by a step," said Polk, explaining why he argued the call. "The umpired disagreed and threw me out of the ballgame. If I had known it was going to be an extra inning game and a lot of decisions were going to need to be made, then I would not have been thrown out. But I thought it was a bad call at that particular time."
Auburn got a career-longest 5.1-inning relief appearance by closer Steven Register, who scattered four hits, struck out five and allowed one run before leaving the game after pitching the 12th inning.
"Register is a nasty hombre," said Polk. "The good thing about this is we probably got him out (for the rest of weekend). Although, I wouldn't be surprised if they let him pitch against a batter in the 9th."
MSU starter Todd Doolittle gave up four runs on six hits. He was followed on the hill by Brooks Dunn, Saunders Ramsey, Cleveland and Corley. Bulldog pitching allowed eight runs on 16 hits with 11 strikeouts and two walks and worked around a season-high five Bulldog errors.
"I think the key was Saunders Ramsey and Brett Cleveland coming in and shutting them down," said Polk. " We made five errors. If we made some plays, we probably finish the game in 9 (innings)."
The win gave MSU its second SEC series win of the season and its ninth win against a ranked opponent this year.
The series concludes Sunday at 1:30 p.m. Senior right-hander Jeff Lacher will pitch for the Bulldogs, while sophomore Josh Bell will throw for the Tigers. The game will be televised regionally on Comcast cable systems.
"(Sunday) will be a test of pitching staffs," said Polk. "We will need 5 or 6 great innings of Jeff Lacher. Jamie Gant can come back and help us. Saunders Ramsey and Brad Corley can pitch to a batter here or there. We still have Jon Crosby, Andy Wilson and Josh Johnson. We brought one extra pitcher this trip than we normally do. We brought 10, plus Corley. Normally, we have nine. So, we have enough pitchers.
"I think that Auburn is in the same boat as us. Dueitt can come back. Madden has already pitched in two games but he didn't throw much. I'm sure that Register, if they need an out, might be involved. I wouldn't be surprised to see (Friday starting pitcher) Mike Felix come back if they need him Sunday."
MISSISSIPPI STATE 9, AUBURN 8 (13 innings)
MSU 000 301 110 000 3- 9-14-5
Auburn 100 140 000 000 2- 8-16-0
WP - Brett Cleveland (2-0). LP - Cory Dueitt (3-4) . SV - Brad Corley (1) . HR - Derek Sain (2) . T - 4:05. ATT - 3,219 .