Tennessee right-hander Steve Crnkovich worked 7.1 innings for his fourth win of the season and the Volunteers held off a late LSU charge to post a 6-5 victory in Lindsey Nelson Stadium.
Tennessee (10-4, 1-0 SEC) won its sixth straight game. LSU (11-4, 0-1) dropped its third straight decision.
The teams meet in Game 2 of the series at 1 p.m. ET Saturday. Left-hander Bryan Morgado (2-1) will start on the mound for Tennessee, while LSU will counter with southpaw Ryan Verdugo (3-0).
Crnkovich (4-0) limited LSU to four runs on six hits in 7.1 innings with one walk and four strikeouts. He left the game with one out in the eighth after LSU designated hitter Derek Helenihi's single cut the Tennessee lead to 6-4.
UT left-hander Jeff Lockwood relieved Crnkovich with runners at the corners and worked out of the jam. Helenihi was thrown out attempting to advance to second base and Blake Dean grounded to first base to end the threat.
The Tigers continued to rally in the ninth as Sean Ochinko reached on a fielder's choice and moved to third on pinch hitter Matt Gaudet's single. Right-hander Aaron Everett relieved Lockwood and struck out DJ LeMahieu for the second out, but Leon Landry grounded an RBI single into right field to reduce UT's lead to 6-5.
However, Everett, who was credited with his second save of the year, forced third baseman Michael Hollander to ground into a fielder's choice to end the game and preserve the victory for Crnkovich.
"I was proud of the way we fought back and had a chance to go ahead in the ninth, but we still dug ourselves too much of a hole," said LSU coach Paul Mainieri.
"Tennessee played a hard-nosed game with a lot of intensity, and we need to come out and match that intensity in tomorrow's game."
LSU starter Jared Bradford (3-1) was charged with the loss as he allowed six runs on six hits in five innings with three walks and a season-high nine strikeouts.
Tennessee broke a scoreless tie in the second inning when catcher Yan Gomes doubled and scored on Lockwood's – who was the starting DH – RBI single. The Vols increased the lead to 2-0 when second baseman Andy Simunic belted his first homer of the year to lead off the third.
Crnkovickh retired the first 12 LSU batters he faced before first baseman Matt Clark launched a mammoth home run – his seventh of the season – to open the fifth inning.
However, Tennessee struck for three runs in the bottom of the fifth as Kentrail Davis delivered a two-run triple and Cody Brown contributed and RBI single.
The Vols led 6-1 in the sixth when Gomes walked and later scored on Tanner Moore's RBI grounder.
LSU began to mount a comeback in the seventh when Dean tripled and scored on Clark's RBI groundout. The Tigers added two more runs in the eighth on Ryan Schimpf's RBI triple and the run-scoring single by Helenihi, setting the stage for the opportunity to take the lead in the ninth.