Sean Barker reached base for LSU in the top of the tenth with a bunt single and advanced to second on Matt Heath's sacrifice bunt. First baseman Clay Harris grounded out to push Barker to third.
The inning -- and the LSU threat -- was seemingly over when David Raymer struck out swinging, but Florida catcher Brian Rose was unable to come up with the ball and threw off the mark to first. Barker crossed home on the play for the winning run.
Tompkins, who came on in relief of starter Lane Mestepey in the eighth, had trouble finding the strike zone in his three innings of work and blew a one-run LSU lead in the ninth. He was able to get the job done in the tenth for the victory and improved his record to 5-0. Mestepey faced two batters in the eighth and allowed eight hits, walked two and struck out one.
The Tigers put up two early runs in the top of the second inning when Heath singled up the middle and scored ahead of Harris' double into the left-field corner. Harris took third on a grounder by Raymer, who was called out a first due to interference. Florida starter Jimmy Ramshaw mishandled a slow roller hit by Chris Phillips, allowing Harris to come home for a 2-0 LSU lead.
Florida cut the lead in half in the bottom of the third after back-to-back singles by Ben Harrison and Mark Kiger and a sac fly to left by Aaron Sobieraj. The Tigers answered right back when Heath scored his second run of the night off a Raymer double after reaching on an error to open the inning.
Two more Florida runs tied the game, 3-3, in the bottom of the fifth inning. Rose led off with a single to right, advanced to second on a sacrifice bunt by designated hitter Ben Harrison and scored when Kiger smoked a 2-2 breaking ball past Wally Pontiff for a stand-up double. Kiger made it to third on the next play when Sobieraj grounded out to second.
Phillips, like he has done successfully numerous times this season, attempted to pick Kiger off third base but threw past Pontiff into left field, allowing Kiger to cross the plate and tie the game.
The Gators threatened to take the lead in the bottom of the eighth by quickly placing a pair of runners in scoring position. Third baseman Pat Osborn reached on a fielding error by Aaron Hill to lead off the inning before first baseman Ryan Shealy ripped a 2-0 Mestepey curveball into the right-field corner.
LSU pitching coach Dan Canevari made the call, and Tompkins entered the game with runners at first an second with no outs.
Pinch hitter Jeff Corsaletti struck out swinging, and Tompkins intentionally walked Matt Goss to load the bases. Second-sacker Aaron Davidson grounded to Harris, who fired the ball home to force out Osborn, and Rose was punched out looking at a wicked Tompkins breaking ball. LSU escaped the inning with the bases full of Gators and game still tied.
The LSU ninth opened with consecutive one-out singles by Phillips and Jon Zeringue. Second baseman J.C. Holt lifted a fly to left, and aggressive base running by pinch runner Rocky Scelfo and Zeringue put runners at second and third for Hill. Hill, who was 0-for-4 on the night to that point, ripped the first pitch he saw through the left side to plate Scelfo and give the Tigers a 4-3 lead.
Tompkins' troubles were even more evident in the bottom of the inning when he walked Florida pinch-hitter Mario Garza on four straight pitches and yielded another free pass to Kiger after being ahead in the count 0-2.
Sobieraj put down a sac bunt, but neither Tompkins nor Pontiff could decide who was going to field the ball, and Florida had the bases loaded for the second time in as many innings, this time with no outs. Osborn sacrificed home the tying run with a fly-out to right before a 6-4-3 double play sent the game into extra innings.
Tompkins still couldn't find the zone in the tenth, and issued a leadoff walk to Jake Riordan before gunning Riordan down at second when Goss tried a sacrifice bunt.
Pontiff robbed Davidson on extra bases with a diving defensive snag, and then ended the game when Rose grounded to third for a double play.LSU (34-16, 15-9 Southeastern Conference) has won 12 of its last 16 league contests and will try for its fifth series victory when it takes on Florida (36-14, 16-9 SEC) Saturday afternoon at 4 p.m. for the second game of the series.