Commodores score seven runs in the first en route to the win.
The Commodores wrapped out 21 hits including four home runs in the winning effort to even the three-game series and improved to 29-22 and 13-13 in SEC play.
LSU's five game winning streak was snapped as the Tigers fell to 33-18 and 12-14 in league action.
David Price gave up two runs on four hits in seven innings of work to improve to 7-4 on the year. He walked five and struck out eight, and now has 130 strikeouts on the season, one shy of the school record set by Doug Wessel in 1971.
Shea Robin's two-run double opened the floodgates in the first off of LSU starter Louis Coleman. Ryan Davis followed with a two-run single and first baseman Brad French capped it off with a three-run homer to left field.
It was the most runs the Commodores have scored in the first inning this season.
Brian Hernandez hit a two-run homer in the second, his first round-tripper of the year, to make it 9-0.
LSU scored a run in the second to make it 9-1.
Quinn Stewart hit a solo homer in the bottom of the sixth, his 21st of the year, to make it 12-2.
Hernandez hit his second homer of the game in the seventh, this one a three-run shot, to extend the lead to 15-2. Ryan Davis then capped off a five-hit afternoon with a solo shot to right-center, his second of the year, to make it 16-2.
"I think everybody was very disappointed after last night's game," said Davis. "We knew that we are a lot better than we have been playing. Everybody had their head on straight and was real determined today."
Several Commodores had multi-hit games on the day, led by Davis' five hits and five RBI. Brian Hernandez had two homers and five RBI and Brad French had three hits and four RBI to help lead the way.
"I got the news that I was going to start at first last night and didn't really get much sleep," said French. "I came out today and just tried to play hard and good things happened."
The 19 runs scored against LSU was the most for the Commodores against the Tigers in school history, besting the previous high of 11 set in 1999 and 1991. The 21 hits was also a season high for VU.
LSU plated two runs in the ninth to close out the scoring in the game.
The teams will play the rubber game of the series tomorrow afternoon at 1 p.m. Sophomore righthander Ty Davis (5-4, 3.81 ERA) will take the mound for Vanderbilt, while freshman southpaw Daniel Forrer (1-2, 6.18 ERA) will throw for LSU.
Vanderbilt 720 201 430 -19 21 0
Price, Zeid (8) and Hernandez, Hawkins. Coleman, Shaffer (2), Byrd (6), Cain (7), Goodwin (8) and Liuzza, Lara. W- Price 7-4, L- Coleman 5-4. SV- None. HR- VU: French (2), Hernandez 2 (2), Davis (2). LSU: Stewart (21).