Fillmore High held St. Bonaventure in check for the first half of Friday night's game before the Seraphs and tailback Topi Sanchez pulled away for a 28-6 victory.
The Flashes (3-3) trailed, 8-6, at halftime of the Tri-Valley League opener after playing a virtual nine-man line and limiting Sanchez to 42 yards and a touchdown.
But after intermission, Sanchez ran for 102 yards and two scores behind the Seraphs' massive line.
"We're always smaller but we come from a tough little town and make a habit of surprising teams," Fillmore Coach John Wilber said. "It was tough to stand up to them for a whole game. They just wore us down."
St. Bonaventure (5-1) opened the scoring with a 10-play, 79-yard drive the second time it had the ball.
Sanchez carried six times for 32 yards on the drive and scored on a three-yard run with three minutes left in the first quarter.
Teohua Sanchez, Topi's brother, completed three passes for 42 yards on the drive.
Fillmore answered with a 16-play, 69-yard scoring drive that ate up a large chunk of the second quarter. Quarterback Chris Goodenough scored from the one.
St. Bonaventure scored midway through the third quarter on a six-play, 82-yard drive capped by a three-yard run by Topi Sanchez.
The Seraphs struck again early in the fourth quarter on an 11-yard pass from Teohua Sanchez to Nick Trujillo.
St. Bonaventure scored with 14 seconds left on another three-yard run by Topi Sanchez.
Teohua Sanchez completed 11 of 17 passes for 140 yards.
Tim Pillado rushed six times for 28 yards and gave the Flashes field position with long kick returns.