A one-point victory over Valle avenged a lopsided conference loss last season.
The difference between St. Vincent and Valle Catholic was one point.
The extra point by Lucas Robinson following St. Vincent's first touchdown, early in the fourth quarter, lifted the Indians to a 13-12 victory in the Mississippi Area Football Conference Blue Division showdown.
Robinson also led St. Vincent's offense Friday with 108 yards rushing on 24 carries.
He had hit field goals in St. Vincent's first two games -- both losses. He was credited with a 40-yard field goal in a 14-10 loss to McAuley Catholic of Joplin, Mo., and his kick was the only scoring in a 38-3 Week 2 loss to Park Hills Central.
For all his rushing Friday, the extra point was the only scoring for Robinson.
Valle, which hammered St. Vincent 26-0 last year in a game that decided the division and Class 1 district titles, scored 3 minutes into the game on Nathan Grass' 8-yard run. But the Warriors missed the kick.
The game remained 6-0 until 3 minutes into the final period, when St. Vincent quarterback Tim Guilliams hit Greg Rellergert on a 25-yard touchdown pass. The kick was good.
Valle (1-2) responded with a 75-yard scoring drive, but again the conversion failed.
Guilliams scored on a 4-yard run with less than a minute remaining to help St. Vincent avoid its first 0-3 start since 1994. He finished with 57 yards passing and 29 yards rushing.
St. Vincent missed on its conversion pass, and Valle's desperation drive ended with an incomplete pass.
Scott City didn't have to look far for a reason it lost 26-20 to East Prairie on Friday night.
The Rams (1-2) made seven turnovers -- losing three of their five fumbles to go along with four interceptions in the fourth quarter.
"You can't win games like that," said Scott City coach Terry Flannigan. "I don't care who you're playing, the defending state champion or the bottom of the bucket, you can't turn the ball over seven or eight times and expect to win."
Scott City turned the ball over twice in the first half inside East Prairie's 20, as the Eagles held on for a 6-0 lead.
"East Prairie's not a bad team, but if we had come out and executed and done what we were supposed to do, we would have won the ballgame," said Flannigan. "Instead, we gave them the opportunities, and they capitalized and did what they had to do.
"We're very frustrated right now, as a group."
The Rams travel to Fredericktown for a nonconference game Friday.
Jackson football coach Carl Gross shortened practices last week following the team's loss to Parkway North on a late touchdown on Sept. 8.
He wanted his players fresh throughout Friday's game, when Jackson built an early lead and held off Vianney 24-6. He told his players to deliver the extra effort from the shortened practices on the playing field Friday.
"I told them they owed me two and a half hours, because that's about what I took off of practice," he said. "They still owe me 30 [minutes] for that fourth quarter."