LSU cornerback Morris Claiborne also had two interceptions and defensive tackle Drake Nevis had the other when defensive back Tryann Mathieu hit Bulldogs quarterback Tyler Russell as he threw. The 6-foot-2, 285-pound Nevis said his interception was not only the first of his college career, but the first he could recall on any level.
"That defense played extremely well from start to finish," LSU coach Les Miles said. "Some of the turnovers were spectacular."
Peterson tipped the ball to himself on both of his interceptions, his first two of the season. He snagged his second one with one hand as he fell before holding it up to the delight of fans.
His first one came as Chris Relf tried to throw deep down the sideline to Arceto Clark, who initially appeared to be open with inside position. Peterson closed quickly and leapt high from behind to break up the pass, then corralled it as it came down and returned it 46 yards to set up a field goal.
"The kid went up and made a heck of a play on our receiver," Mississippi State coach Dan Mullen said. "Our receiver has to go up and take it away from him in those situations."
Peterson also returned a kickoff 39 yards. He nearly got in the end zone on his only opportunity to field a punt, but a penalty wiped that return out. Peterson already has one punt return for a score, which came in the season opener, when he combined for 257 kickoff and punt return yards against North Carolina.
Russell was intercepted three times. Chris Relf, who played the first half and was shaken up on a scramble early in the third quarter, threw the other two. Mullen said Relf was cleared to return to the game, but there was no reason risk it because Russell was playing just as well, having led the Bulldogs' only scoring drive.
Vick Ballard's 2-yard TD run got Mississippi State (1-2, 0-2) as close as 12-7 in the third quarter before LSU pulled away.
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Jefferson came into the game looking to silence a crescendo of criticism that rose after he went 8 of 20 for 96 yards a week earlier at Vanderbilt.
Although he moved the Tigers inside the Bulldogs 35 four times in the first half, all four possessions ended in field goals for a 12-0 halftime lead. On the fourth of those drives, the Death Valley crowd booed the offense's inability to get in the end zone.
Jefferson was mostly conservative with his throws, going 10 of 16 for 97 yards. It was his second straight game with less than 100 yards passing and no touchdowns.
"I feel like my performance was a lot better compared to a week ago," Jefferson said. "We have an absolutely stellar defense and they put us in great positions with good field position throughout the night."
When Jefferson finally scored, he stood to face fans behind the end zone while brushing both hands across his chest as if presenting his No. 9 jersey.
Mullen started Relf, an option quarterback, in an effort to counter an LSU pass rush that had accounted for 10 sacks in its first two games.
But Relf was sacked by Mathieu on the Bulldogs' first drive and was intercepted by Peterson on his second.
Russell came in for the first time early in the third quarter and completed passes of 17 and 19 yards on the next two plays, setting the stage for Mississippi State's only score.
"There were a lot of mistakes on offense and a lot of protection errors," Bulldogs offensive lineman Quentin Saulsberry said. "Defense stuck it out, but we didn't make the plays we were supposed to make and that is when we have to go back to the basics."
Top 25 Overview
It was over when... Jordan Jefferson ran for a 16-yard score to push the lead to 19-7 in the third quarter.
Gameball goes to... Josh Jasper. With 17 points, LSU's kicker outscored the Bulldogs all by himself.
Stat of the game... 1991. Mississippi State has not won in Baton Rouge since 1991.