Jordan Davis completed 12 of 23 passes for 162 yards and a touchdown in his first career start while freshman Trey Ragas scored on a 54-yard run in the first quarter as Louisiana (1-0) scored its most points in a season-opener in the modern era.
In the first meeting between Louisiana and SLU (0-1) since 1981, both teams quickly made up for lost time with a combined six touchdowns in the first quarter, including kickoff returns of 97 and 100 yards by Calais and a 54-yard run by Ragas.
SLU answered Calais' kick return to open the game by driving 68 yards in seven plays with Eugene Bethea capping the drive with a 42-yard TD run. The Lions took their first lead of the night after forcing the Cajuns to punt with Max Lyons returning a punt return 60 yards for a TD.
Bethea added a 1-yard TD run with 3:09 remaining in the first quarter that gave SLU a 21-14 lead before Calais scored his second TD of the night with a 100-yard return, tying Darryl Surgent (2013 vs. Kansas State) and Jeryl Brazil (2015 vs. Texas State) for the longest return in school history.
Davis tossed a 15-yard TD pass to Ryheem Malone to give Louisiana a 28-21 lead with 13:47 remaining in the second quarter with Dion Ray adding a 1-yard TD run for a 35-28 lead with 10:01 remaining.
Jordan Wright capped a 10-play drive for the Ragin' Cajuns with a 3-yard TD run in the third quarter before Mitchell's first career TD gave Louisiana a 49-42 lead with 8:41 remaining.
After Sam Geraci's punt was downed at the SLU 5 with 3:16 remaining, SLU drove 95 yards in 10 plays with Lorenzo Nunez hitting Nih-jer Jackson on a 29-yard TD pass with :42 seconds remaining. The Lions attempted a potential go-ahead two-point conversion, but Nunez was flushed from the pocket, fumbled and Joe Dillon scooped up the miscue and scored on a defensive PAT to seal the win.
Tracy Walker recorded 10 tackles to lead Louisiana with T.J. Posey adding eight. Dillon added a sack for the Ragin' Cajuns with freshman Bralen Trahan picking off a Nunez pass for his first career interception.
Bethea rushed for 187 yards and two touchdowns for SLU, which gained 343 yards on the ground and controlled the football for 34 minutes. Nunez completed 15 of 25 passes for 171 yards for the Lions with Juwan Dickey catching eight passes for 99 yards.