BATON ROUGE, La. -- LSU played without its best player and might have found a couple of new key players in the same game.

All-America running back Leonard Fournette rested a sore ankle and Derrius Guice replaced him and ran for 155 yards and a touchdown and quarterback Danny Etling came off the bench to spark the offense in his Tigers debut as No. 21 LSU defeated Jacksonville State 34-13 in a non-conference game Saturday night in Tiger Stadium.

Guice, a sophomore who had just one 100-yard game previously, became the focal point of the offense as Fournette rested the ankle that he sprained in preseason camp three weeks ago and aggravated in a 16-14 loss to Wisconsin on Sept. 3.

"Guice showed that he's a pretty special back in and of himself," LSU coach Les Miles said.

The LSU offense didn't come to life, though, until Etling, a junior transfer from Purdue, replaced struggling Brandon Harris at the start of the second quarter. Etling led a 70-yard touchdown drive on his first possession, triggering touchdowns on four consecutive LSU possessions as the Tigers took control with a 27-10 halftime lead.

Miles said he made the change because Harris, a junior making his 15th career start, didn't seem comfortable.

Etling, who completed 6 of 14 passes for 100 yards with a touchdown and an interception, ran 2 yards for a touchdown that gave LSU a 34-10 lead after three quarters. He was 0-for-6 with an interception in the second half.

"He wasn't perfect by any means," Miles said of Etling. "But for his first playing time he certainly performed well to a point."

Miles wouldn't say who he would start when the Tigers (1-1) play their SEC opener against Mississippi State next Saturday in Tiger Stadium.

"The season is a long season and we're going to need both of them," Miles said. "I would expect both guys would understand it's a competition."

As for Fournette, who missed the first game in his three-year career, Miles said he expected him to be ready "pretty quick."

The Tigers held just a 13-10 lead late in the second quarter before getting a handle on Jacksonville State's dual-threat quarterback Eli Jenkins and holding the Gamecocks scoreless from that point until Cade Stinnett kicked a 28-yard field goal with 4:27 left in the game.

Jenkins completed 17-of-35 for 248 yards and ran 18 times for 82 yards.

The Gamecocks, a perennial FCS power, fell to 1-1 heading into their home game against Coastal Carolina next Saturday.

"We gave up too many explosive plays," JSU coach John Grass said. "But I was proud of our guys. The main thing is we matched their physicality and kept fighting for four quarters."

JSU took advantage of field position resulting from LSU going three-and-out on Harris' two possessions and drove 33 yards to set up Stinnett's 30-yard field goal on the first play of the second quarter.

Etling replaced Harris on the Tigers third possession and immediately gave the offense a lift, throwing a 46-yard touchdown pass to tight end DeSean Smith that gave LSU a 6-3 lead after the extra point was blocked.

"That was pretty nice," Etling said, "especially since we were down at the time."

The Tigers increased the lead to 13-3 on their next possession as Guice ran 4 yards for a touchdown.

On the first play after the kickoff, the Gamecocks responded with a 76-yard touchdown pass from Jenkins to Krenwick Sanders to trim the lead to 13-10.

LSU answered with a 2-yard touchdown run by Bry'Kiethon Mouton and a 60-yard punt return for a touchdown by Tre'Davious White that gave it a 27-10 halftime lead.

"To me the difference in the game was after we cut it to 13-10 on an explosive play and then they came right back and scored two quick ones," Grass said. "I thought if we could have gotten to halftime down 13-10 we would have been sitting pretty good."

On his return, White ran backward 20 yards before turning upfield and finding running room.

"He should get double credit for that running," Miles said.

NOTES: The game started 55 minutes late because of a weather delay. It was the second consecutive year that the Tigers' home opener was disrupted by weather. Last season's opener against McNeese State entered a rain delay after 10 plays, did not resume that night and was never made up. ... Jacksonville State junior WR Kevin Spears is a native of New Orleans who spent three years in the LSU program. He played in 12 games before transferring after the 2015 season. His 42-yard reception in the third quarter was his first catch in Tiger Stadium. ... Jenkins surpassed Clay Green into fifth place among JSU's career rushing leaders (2,995). ... This was the first meeting between LSU and Jacksonville State.