"We did what we had to do, and we're moving on," said Naji, a senior tight end and defensive end. "That's what counts most."
After a second-minute interception, La Salle (11-1) scored six straight times. Naji's 28-yard, second-quarter touchdown grab was part of the explosion.
Naji said that the previous week's win, a 28-27 overtime decision against archrival St. Joseph's Prep, "took a lot out of us emotionally. But we were able to get past that. We weren't going to allow a letdown."
After a bye next weekend, the Explorers will play District 11's Parkland or District 2's Delaware Valley in a state quarterfinal Dec. 1 at Northeast.
"There are no more easy games for us," senior two-way lineman Tom Spiteri said. "We have to maintain our focus the rest of the way."
Frankford's chance to take an early lead, after moving to the La Salle 6-yard line, was halted by Dad Poquie's end-zone interception. The Public League champs never recovered.
"If we score there, it changes the whole complexion of the game," Pioneers coach Will Doggett said. "We had a dumb penalty [offsides call] kill the drive."
With scoring passes to Jimmy Herron (77 yards) and Sean Coleman (26 yards) sandwiching a 15-yard TD burst by Jordan Meachum, the Explorers comfortably led, 23-0, early in the second quarter.
La Salle's Chris Kane completed 6 of 9 throws for 152 yards and three TDs. Meachum netted 147 yards on just seven attempts.
In the first half, while helping limit Frankford (8-3) to 24 yards rushing and 62 passing, the 6-foot-2, 240-pound Naji and Spiteri recorded sacks.
Frankford's Tim DiGiorgio posted 170 of his 242 passing yards after intermission. The Pioneers were without tailback Damion Samuels (ankle injury) and lost receiver/linebacker Wydell Compton (knee) early in the game.
La Salle 16 21 0 0 – 37
Frankford 0 0 6 14 – 20
L: FG Ryan Winslow 27
L: Jimmy Herron 77 pass from Chris Kane (kick failed)
L: Jordan Meachum 15 run (Winslow kick)
L: Sean Coleman 26 pass from Kane (Winslow kick)
L: Jon Naji 28 pass from Kane (Winslow kick)
L: Nick Buckley 1 run (Winslow kick)
F: Rene Herrera 62 pass from Tim DiGiorgio (kick failed)
F: Quinton Ellis 47 run (Marquis Poston run)
F: Denzel Turbeville 5 pass from DiGiorgio (pass failed)
Contact Rick O'Brien at robrien@phillynews.com, or @ozoneinq on Twitter. Read his blog, "The O'Zone," at www.philly.com/ozone
