LAFAYETTE — A double dose of motivation for St. Augustine running back Leonard Fournette was more than St. Thomas More could handle.

Fournette more than lived up to his billing as one of the top running backs in his class, propelling No. 10 St. Augustine to a 40-14 victory Friday over No. 7 St. Thomas More at Cougar Stadium in Class 4A state regional playoff action.

Fournette, a junior, had a season-high 340 yards on 31 carries and scored three touchdowns to lead the Purple Knights (9-3) into a quarterfinal matchup with No. 2 Karr, a 35-14 winner over Northwood, in New Orleans next weekend.

“This was a hump game,” Fournette said. “Last year we lost in the second round (24-23 to McDonogh #35), and my freshman year we lost to St. Thomas More (in a Class 5A quarterfinal), so it was kind of a revenge game for me.”

Fournette’s third touchdown — a punishing 16-yard score — capped a stretch of 19 unanswered points in the last 15 minutes, letting St. Augustine turn a 21-14 lead into a comfortable victory and its fourth win in the past five games.

“We knew who he was; we knew what the challenge was,” STM coach Jim Hightower said. “They were just better than us. There were an awful lot of third and fourth down plays, and (Fournette) busted them wide open.”

Fournette, who already has more than 100 scholarship offers, pushed his season rushing total near the 2,000-yard mark (at 1,975) and reached the 30-touchdown plateau.

If Fournette’s opening half — 12 carries for 139 yards wasn’t enough — the 6-foot-1, 220-pounder was even better in the second half with 20 carries for 201 yards and two scores.

“I have seen some awfully good ones, and he’s as good as any I’ve seen,” Hightower said. “His size … he’s monstrous. He’s definitely got that drive. A lot of times we hit him with two or three guys and came out of it. He’s definitely a special back.”

STM (8-4) pulled within 21-14 with 6:30 left in the third quarter on Brandon Bergeron’s 16-yard, fourth-down screen pass to Matthew Gumpert following a blocked punt by William Trotter and recovery from Zach Comeaux.

St. Augustine, which outgained STM 392-230, answered with an eight-play, 80-yard drive that Fournette finished with a 40-yard scoring run on third-and-12 and added an 18-yard score to make it 35-14 with 5:52 remaining.

For the second time in the game, the Knights, who forced four turnovers, returned an interception for a touchdown when Austin Craig did the honors from 49 yards less than two minutes later.

Bergeron, who had thrown one interception in his past four games, was picked off three times and battered by a St. Augustine defense that sacked him seven times, including five by Blaise Brown.

He was 21 of 35 for 189 yards, with senior Seth Kelly leading the way with eight catches for 75 yards and a TD.

“They’ve got some men out there, and they came across the ball hard,” said Hightower, whose team had a seven-game win streak snapped. “It’s not a matter that we didn’t know and didn’t prepare for it. They just outmanned us.”

St. Augustine led 8-0 one play into the game when linebacker Ashton Hillard brought back an interception 36 yards and Fournette ran in the two-point conversion.

STM overcame its inauspicious start — that interception and a fumble in its first two plays — to close to 14-7 on Bergeron’s 6-yard TD pass to Kelly ... only to have St. Augustine take the kickoff and extend its lead to 21-7 on Jermaine Robert’s 92-yard return.

“It meant so much to me because people were doubting us,” Fournette said. “We had to come out and prove everybody wrong.”