Daquan Mack, Pennsbury's bruising fullback (6-foot-2, 245 pounds) led the Falcons' wing-T scheme, gaining 100 yards on 25 carries, including a 5-yard TD run at the 5-minute, 2-second mark of the third quarter that put Pennsbury up for good.
The Hawks (4-1 overall, 1-1 league), which took a 10-6 lead into the locker room at intermission, had the ball for just four series in the second half.
The Falcons put up only one score after the break, but sustained drives long enough to kill the clock and keep the South offense - which had averaged 28.5 points through its first four games - off the field.
Pennsbury's best defense, it seemed, was keeping that offense on the sidelines as rain began to pour late in the third quarter.
"We weren't looking for big runs, because it was raining," Mack said. "We just took it ground and pound - just chunk after chunk after chunk."
South quarterback Brian Donnelly ran for an uncharacteristic 14 yards on seven attempts. He came in averaging 9.5 yards a carry and 147.8 a game.
Donnelly did score South's lone touchdown, on a 1-yard sneak in the second quarter. He was 4-for-11 passing for 46 yards, with an interception and two lost fumbles.
South's wishbone attack garnered 190 total yards on the ground. The Hawks, trailing late but having the ball with 2:10 to go, were forced to throw late in search of a comeback.
The effort proved futile, and Donnelly was sacked by Shawn Pepper to end South's night.
Adam Lewis accounted for the Falcons' other touchdown, going 30 yards on a reverse in the second half. The extra-point hold was botched, and a kick attempt was never made.
Lewis finished with 67 yards. His touchdown gave Pennsbury a 6-3 advantage. South's Ben Solis had kicked a 26-yard field goal four minutes prior.
Pennsbury (4-1, 2-0) took a knee from then on to seal its fourth straight victory since a loss to District 11's Easton, a PIAA Class AAAA state quarterfinalist last season, in its opener.
The win avenged the Falcons' 24-0 loss at South last year and pushed their lead in the all-time series to 3-1.
Pennsbury coach Galen Snyder tried to conceal a big grin after the big win.
"They took it to us pretty good last year," Snyder said. "We owed them this one."
Council Rock South 0 10 0 0 – 10
Pennsbury 0 6 7 0 – 13
CRS: FG Solis 26
P: Lewis 30 run (kick failed)
CRS: Donnelly 1 run (Solis kick)
P: Mack 5 run (Kniaziewicz kick)
Contact Evan Burgos at rallysports@phillynews.com.