Horton's touchdown capped a nine-play, 58-yard drive as Kentucky (1-0) built a 24-7 lead at halftime and led, 33-17, after three quarters.
Louisiana (0-1) battled back from a 21-0 deficit early in the second quarter as the Ragin' Cajuns scored a pair of second-half touchdowns by Torrey Pierce before a 23-yard scamper by Jalen Nixon and two-point conversion by Elijah McGuire tied the game at 33-33 with 7:36 remaining in the game.
"I'm really proud of this football team," head coach Mark Hudspeth said. "We brought 60 scholarship players up here to play an SEC team … 60. We left a lot of good players at home and we lost (senior receiver) Al Riles in the first quarter. These kids never let go of the rope and found a way to climb right back in this game. That is what is our program is about.
"We had some opportunities to win the game. Some young guys showed that they were young and some of key guys didn't have their best game either. But we overcame it all and had a chance to beat an SEC team on the road. I'm very disappointed that it didn't happen, but of all of our first games in the past five years, this one shows me more promise for a season by the way this group battled, the resiliency that they showed. They never quit."
Kentucky scored on the game's first play when Boom Williams raced 75 yards untouched for a quick 7-0 lead. The Wildcats added a second touchdown two possessions later when Patrick Towles connected with Garrett Johnson for a 35-yard scoring pass to cap a seven-play, 99-yard drive that gave Kentucky for a 14-0 lead with 6:17 remaining.
Louisiana got on the board with 8:33 remaining in the second quarter when Brooks Haack capped a 13-play, 75-yard drive with a 4-yard touchdown run.
After Austin MacGinnis converted on his second field goal of the game to give Kentucky a 27-7 lead with 9:54 remaining in the third quarter, the Ragin' Cajuns began their comeback.
Freshman Stevie Artigue booted a 31-yard field goal – the first of his career – that cut the lead to 27-10 at the 6:04 mark before Kentucky answered when Towles connected with Blake Bone on a 5-yard scoring pass for a 33-10 lead with 3:47 left in the period.
Pierce, who was playing in his first game since a season-ending injury against Texas State, then took over in recording his first career 100-yard rushing game. The senior took a handoff from Haack and scampered 56 yards to cap a five-play, 74-yard drive and cut the Wildcat lead to 33-17.
The Ragin' Cajuns then capitalized when MacGinnis missed on a 46-yard field goal and drove 71 yards in eight plays to cut the lead to 33-25. McGuire converted a third-and-1 play on a 2-yard run to the UL 48 and Jalen Nixon gained four yards and second-and-2 and was aided by a late hit moved the ball to the UK 31.
Two plays later, Pierce slipped past the Wildcat defense and scored from 26 yards out and Nixon's pass to McGuire on the two-point conversion was good with 11:39 left.
After giving up 303 yards to the Wildcats in the first half, the Ragin' Cajuns defense got into the act as Tracy Walker picked off Towles at the UL 48. A 15-yard penalty would push the ball back to the UL 33, but the Ragin' Cajuns would drive 67 yards in eight plays to knot the game.
Nixon, who came off the bench and was 4-for-4 for 38 yards, connected with Gabe Fuselier on a 23-yard pass to UK 42 on second-and-8 and McGuire converted a third-and-1 for the Ragin' Cajuns with a 3-yard run to the 30.
Three plays later on third-and-3, Nixon would race 23 yards untouched to the end zone and McGuire would convert his second 2-point conversion of the night off a "Statue of Liberty" call with 7:36 remaining.
A 38-yard punt by Steven Coutts and 5-yard penalty by the Ragin' Cajuns would give Kentucky the ball at their own 42 with 4:37 remaining. The Ragin' Cajuns were called for a pass interference call that put the ball on the UL 24 before a holding penalty gave Kentucky the ball at the UL 14.
After Horton's TD, the Ragin' Cajuns had an opportunity to tie the game, but Haack's desperation heave on fourth down at the UL 42 was intercepted by Josh Forrest at the UK 10.
"We're going to rally and we're going to build on this," Hudspeth said. "Our defense … once we settled down, we played some really good defense. Second half, I thought was an unbelievable team effort. We beat them in the second half. Couldn't be more proud of this group right here. There's a lot of fight in these guys. We're going to get better."
Haack, making his second career start, completed 22 of 32 passes for 194 yards. Pierce gained a career-high 110 yards on the ground for the Ragin' Cajuns with McGuire finishing with 86 yards on a career-high 27 carries.
Freshman Gary Haynes caught a game-high eight passes in his debut for Louisiana with Fuselier catching a career-high seven passes. Jamal Robinson, playing in his first game since a season-ending injury last season, caught six passes for 61 yards.
Dominique Tovell recorded seven tackles with two sacks and five tackles for loss for the Ragin' Cajuns with Zachary DeGrange totaling five stops with a sack.
Towles, who was 6-for-16 through the air with an interception in the second half, finished 16-for-34 for 257 yards and three touchdowns. Williams led UK with 135 yards on the ground with Johnson catching a team-high five passes for 85 yards.