BATON ROUGE, La -Ciara Bryan took the early lead for the Cajuns with a solo shot in the first inning.
But it was all LSU after that as the Tigers put up five runs in the first inning off Louisiana senior pitcher Summer Ellyson.
Ellyson was relieved by Vanessa Foreman in the first frame.
LSU recorded 17 hits on the day, with pitcher Shelbi Sunseri 3-for-4 with three RBI, a double and a home run.
LSU secured its spot in the regional final.