"We needed it, we wanted it and we got it," senior Casey Brown, who had three of Casey's seven sacks, said.
McGinnis also completed both of his pass attempts for a total of 36 yards. Rex Delk had 104 yards rushing and two touchdowns - one in the second quarter and one in the third - before leaving the game with 10:31 to play in the fourth quarter after bruising his right shoulder.
Tristan Harris scored Casey's other touchdown with a 33-yard run in the fourth quarter.
It was the third straight win for Casey, which moves on and will play at the winner of tonight's Western-DeSales game in the first round of the Class AA playoffs next week.
The Rebels showed flashes of many things Thursday, from a methodical offense that moved 84 yards in 18 plays and ran eight minutes, 16 seconds off the clock to a new defensive look that led to the seven sacks.
Casey took over on its own 13 and moved the ball to the Russell 3, never gaining more than 12 yards on a play and never getting more than nine on any running play, before turning the ball over on downs.
That was the first of two times Casey would reach the red zone in the first half and come away with no points. The second time was on the final drive of the second quarter.
The Rebels had a first-and-goal from the Russell 1, but were called for a false start. McGinnis picked up four yards on a sweep, but Andrew Allen was stopped short of the goal line as the half expired.
"It was poor execution that hurt us," Stephens said. "We get a false start penalty and then we run another play and for some reason, a block we usually make, we miss. It's really just execution."
"We went in at halftime and I told them, 'You guys aren't playing with all you've got,'" McGinnis said. "Coach said before the game we had to have 11 guys playing together, and that's the only way we're going to make it anyway. I was so mad when we had it on the one-foot line and we couldn't stick it in there."
The offense got untracked in the fourth quarter, scoring three times to put the game out of reach.
Casey's defense earned praise from Stephens after dealing with a new formation. The Rebs usually go with a 5-2 alignment, but switched to a 4-4 defense after illness and injuries changed the personnel.
Now, Casey turns its attention to the second season.
"We're a pretty good football team sitting at 4-6 and going into the playoffs," Stephens said. "I think we'll surprise some people if they don't watch us."
"I'm not ready for the season to end," McGinnis said. "I hope they're ready to start stuff next week, go to Louisville and maybe surprise some people. If we win, we'll get to play Corbin again. I'd like to play Corbin again."