COLLEGE STATION, Texas — How fleeting leads are on the road the Southeastern Conference.

Brian Kelly has said it many times before, winning in an unfriendly SEC stadium is difficult and while No. 7 LSU football trotted off the field at halftime at Kyle Field with a 10-point lead, that lead evaporated in the second half after Texas A&M made a quarterback change in a 38-23 win Saturday night.

The No. 14 Aggies made a change at quarterback to freshman Marcel Reed early in the third quarter, and the zone read ate the Tigers' defense alive. In the battle for the top spot in the SEC, it was A&M that stunned LSU with quick jabs as Reed ran by the Tigers.

LSU (6-2, 3-1 SEC) dropped its first game in league play and gets an off week before rival Alabama comes to Tiger Stadium in two weeks.

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LSU defense could not stop Texas A&M quarterback Marcel Reed

LSU defensive coordinator Blake Baker and his defensive guys were able to completely hem up starting quarterback Conner Weigman, who managed just 64 yards on 6-for-18 passing in two quarters. A&M coach Mike Elko decided to make a switch to Reed, who mostly operates in a zone read scheme.

Baker and his defensive players struggled to adjust to the different scheme as Reed ran for three touchdowns in the second half along with 48 yards on just six rush attempts.

The varying styles between Weigman and Reed were jarring and it completely caught LSU's defense off guard.

Garrett Nussmeier tosses interceptions that Texas A&M cashed in

By the end of the second quarter, LSU quarterback Garrett Nussmeier had thrown for 259 yards and two touchdowns. He was rolling, as was LSU's offense. A tale of two halves.

Nussmeier, who came into Saturday night's game in College Station with six picks on the season, made some ill-advised decisions in the third quarter and threw three interceptions, the first two to B.J. Hayes and the third to linebacker Taurean York, setting up Texas A&M in short field positions all three times.

The turnovers led to 21 points, which was the difference on the scoreboard.

Nussmeier did throw for 405 yards, his second 400-yard passing game this season.

Offensive line depth tested for LSU in loss at Texas A&M

Late in the second quarter, LSU senior left guard Garrett Dellinger went down what an apparent lower leg injury. Dellinger was seen still dressed in his pads on the sideline in the second half but did not return to the game.

Freshman Paul Mubenga was tasked with filling in for Dellinger, who's been a multi-year starter for the Tigers. Mubenga had a difficult job trying to protect Nussmeier from some of A&M's best players in defensive tackle Shemar Turner as well as Albert Regis.

Nussmeier was hit a couple of times in the second half and A&M star defensive end Nic Scourton sacked him in the fourth quarter.

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Cory Diaz covers the LSU Tigers for The Daily Advertiser as part of the USA TODAY Network. Follow his Tigers coverage on Twitter: @ByCoryDiaz. Got questions regarding LSU athletics? Send them to Cory Diaz at bdiaz@gannett.com.

This article originally appeared on Lafayette Daily Advertiser: Turnovers tumble LSU football in rattling defeat to Texas A&M