The victory completed a three-game SEC series sweep for the Rebels, who improved to 26-15 overall and 10-8 in league play.
LSU, which was swept on the road for the first time since 2001 at Arkansas, fell to 26-16 overall, 6-12 in the SEC.
The Tigers return to action at 6:30 p.m. Wednesday when LSU plays host to the University of New Orleans.
"We just have to keep working and teaching to get this young club back on track," said LSU coach Smoke Laval. "This has obviously been a rough stretch, but we still have a chance to recover and move forward."
Ole Miss catcher Justin Brashear led off the Ole Miss eighth with a homer off of LSU reliever Chase Dardar to tie the game at 8-8. Dardar then walked second baseman Justin Henry before he was replaced on the mound by Will Harris.
Harris gave up consecutive singles to C.J. Ketchum and Chris Coghlan to load the bases before shortstop Zack Cozart delivered an two-run double to give the Rebels a 10-8 lead.
Right fielder Mark Wright later added a sacrifice fly to increase the advantage to three runs.
Catcher Matt Liuzza and third baseman Buzzy Haydel started the LSU ninth with consecutive singles, but Ole Miss reliever Cody Satterwhite retired the next three LSU hitters to end the game.
Sattterwhite (5-2) picked up the win, allowing no runs on two hits in two innings with one walk and no strikeouts.
Dardar (5-2) charged with the loss as he surrendered three runs on three hits in three innings with three walks and three Ks.
LSU trailed 6-2 before scoring five runs in the top of the sixth to take a 7-6 lead. The Tigers were aided by three walks and an Ole Miss error, and pinch hitter Jason Ogata's two-run double highlighted the rally.
The Tigers increased the lead to 8-6 with a run in the seventh as centerfielder Jarred Bogany lined an RBI single.
Ole Miss closed the gap to 8-7 in the bottom of the seventh on DH Jon-Jon Hancock's run-scoring single, setting the stage for the Rebels' four-run eighth.
Break out the brooms: Tigers swept
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