LSU (14-3), which recorded its sixth shutout of the season, opens Southeastern Conference play at 7 p.m. Friday when the Tigers play host to No. 21 Mississippi State in Alex Box Stadium.
Northwestern State dropped to 5-11 on the year with Wednesday's loss.
LSU starting pitcher Austin Nola (3-0) recorded the victory. He fired three strikeouts in two shutout innings on 31 pitches. The Tiger pitchers allowed six hits and struck out 10 Demon batters.
Starter AJ Funk (0-1) was charged with the loss for Northwestern State. The right-hander pitched 1.1 innings, allowed four runs (three earned), three hits and one walk.
Rightfielder Raph Rhymes led LSU with two hits and four RBI, and he now has 25 RBI for the year. First baseman Mason Katz chipped in three more RBI and second baseman Casey Yocom scored three times.
"I thought that overall we played a pretty solid ball game, and I was very pleased with the performance of our bullpen," said LSU coach Paul Mainieri. "All of the relievers pitched effectively, and that was something we needed to see heading in to SEC play this weekend."
Nola went right to work in the top of the first inning. After striking out Will Watson and forcing Ray Frias to ground out to third, he allowed only his second walk of the season. He responded and struck out cleanup hitter Ryan Westbrook on four pitches.
LSU put two on the board in the bottom of the opening frame. Center fielder Chris Sciambra, in his first start in the leadoff spot, beat out an infield single and moved to second on Yocom's walk. Katz moved both runners forward with a groundout to short.
Rhymes punched a hard grounder to short that allowed Sciambra to score. With runners on the corner and one out, catcher Ty Ross placed a sacrifice bunt down the first base line and plated Yocom.
The Tigers kept the bats going in the second and added three more. Back-to-back one-out singles by designated hitter Grant Dozar and left fielder Alex Edward chased Funk. Reliever Zach Winchester forced Sciambra to fly out to left, but a walk to Yocom loaded the bases. Katz walked to plate Dozar.
Rhymes smacked a hard groundball single through the hole between third and short to score Edward and Yocom.
Pitcher Kevin Berry replaced Nola in the third and did not allow a run in his inning of work.
Brent Bonvillain entered the game for Berry prior to the fourth inning and struck out Purdy. Westbrook lined a single to center and moved to second when Collin Bear reached safely after an error by Katz. Nick Hinojos hit a liner to center that was fielded by Sciambra, but allowed Westbrook to advance to third. A walk to Nick Doughty loaded the bases. Drew Helenihi hit a grounder to first to end the threat.
LSU's offense went back to work in the bottom of the fifth against the Demons' JP Clifton. Ross walked to lead off the inning and moved to second on Nola's single to left. Hanover placed a perfect bunt and beat out the throw to load the bases. Right-hander Andrew Adams entered the game for Northwestern State and LSU countered with pinch hitter Jackson Slaid.
Slaid smoked a hard groundball to third that was mishandled by the third baseman and allowed Ross to score. After Edward popped out to second, Sciambra knocked a single off the handle of the bat into left field. Austin Nola scored on the play and kept the bases loaded for Yocom, who drew a bases-loaded walk.
Katz slapped a single up the middle to bring in Slaid and Sciambra. Rhymes drove home Yocom on a single to right center and Katz moved to second, which chased Adams.
Jared Foster entered the game as a pinch runner for LSU and the Demons inserted new pitcher Austin Robson. Ross grounded out and advanced Katz and Foster into scoring position. Pinch hitter JaCoby Jones was hit by the next pitch and loaded the bases. Pinch hitter Evan Powell walked to bring in Katz.
The Tigers added a 13th run in the bottom of the seventh. Foster led off the inning with a single to right and moved to second on a wild pitch. Catcher Jordy Snikeris ripped a single to right and moved Foster to third. Jones grounded out to short and plated Foster.