The Razorbacks (22-15, 7-8 SEC) scored four runs in each of the first and fifth innings and smacked a pair of homers to fuel the rout. Kyle Bouman lasted only one inning in his second start since returning from injury, and the LSU (27-9-1, 8-6-1) offense failed to keep pace, producing four runs on four hits and seven walks.
"It was obviously just not our day today," said LSU coach Paul Mainieri. "It's one of those days where nothing went right."
It was an ugly start for Bouman as Arkansas jumped on him in a hurry. Tyler Spoon and Andrew Benintendi had consecutive hits to begin the game, and a walk to Joe Serrano loaded the bases without an out.
Bouman managed to induce an infield fly for the first out of the inning, but Blake Baxendale did the damage in the next at-bat with a grand slam that cleared the left field bleachers.
"Kyle Bouman's not a strikeout pitcher, and the only way he's going to have success is if he stays down in the zone," Maineiri said. "Unfortunately, he didn't get down in the zone and right out of the gate, they hit him hard."
Cody Glenn replaced Bouman after that rough first inning and tossed a pair of perfect frames before surrendering a run in the fourth. He walked Eric Fisher and a single by Bobby Wernes put runners on the corners with one out.
Jake Wise drilled one back to the mound, Glenn fielded it and held the runner at third, but an errant throw to second allowed the run to score.
"Had he turned a double play to end that inning, he would've had three wonderful shutout innings," Mainieri said.
Arkansas only led 5-2 at that point, but the Razorbacks really broke it open in the fifth. Glenn walked the first two batters of the inning before giving way to Brady Domangue. He surrendered a run on a sacrifice fly in the next at-bat.
Baxendale then drove in his fifth run of the game with a double into the right field corner, and Eric Fisher followed that with a two-run blast, his third home run of the series.
The Razorbacks tacked on a run in the eighth with a sacrifice fly by Benintendi to reach double digits, only the second time an LSU opponent has done so this season.
"Once we started running some different [pitchers] out there, they got to us," Mainieri said. "They took control of the game. It's just hard to sweep series in this league."
That large deficit was too much for the LSU offense to overcome, as the Tigers are now 0-6 when the other team scores at least five runs.
Jake Fraley did drive in a pair in the second with a single up the middle. Andrew Stevenson added another on a sacrifice fly in the sixth, and Kade Scivicque brought in one with a two-out single in the seventh.
The Tigers did win the series though after earning victories on Friday and Saturday. LSU finishes the weekend in third place in the SEC West, 1.5 games behind division leader Alabama.
LSU will hit the road for its next four contests, meeting Southern Miss on Tuesday in Zephyrs Stadium for the Wally Pontiff Classic. The Tigers' next conference series will start Thursday against Ole Miss in Oxford.
Mainieri hinted after the game they may be looking for a new Sunday starter for this upcoming series against the Rebels.
"Your momentum is your starting pitcher, and if he doesn't perform well, you put yourself in a bind right away," Mainieri said. "That's what happened to us today, but we just have to shake it off and get ready for a very challenging week."