Butler completed 11 of 13 passes for 88 yards in the half. He ran for 21 yards on four carries.
Iowa added a pair of third-quarter scores on a 47-yard catch and run by Deville and a 29-yard run on an end-around by McQuinton Montgomery.
“We just had to settle in,” Iowa head coach Tommy Johns said. “We were a little antsy at first and lined up incorrectly a few times in the first quarter and paid for it.
“We were worried about (Harris) all night. Bossier did a good job, give credit to them. But we finally settled in and the players and coaches deserve credit for a good week.”
Iowa finished with 268 rushing yards. Young had 128 yards on 18 carries.
“We knew our offensive line play was going to be critical coming in since they do a lot of blitzing,” Johns said. “Our offensive line did a tremendous job and Young ran harder than ever tonight. It was a real turning point for him. It was a big night for every guy up front, they did a great job.”
Butler finished with 101 passing yards and 28 rushing yards for Bossier. Harris had four receptions for 65 yards.
Deville had 83 receiving yards and 41 rushing yards for Iowa. Lebleu threw for 101 yards on 4-of-6 passing.
It was Iowa’s first playoff win since 2017.
The Yellow Jackets lost 20-14 at West Feliciana in the 2015 quarterfinals. The Jackets reached the 1-yard line in the final minute but didn’t score.