The Red Devils passed for 342 yards and four touchdowns in a 36-14 win over Grandview a week ago with Montgomery at the helm.
With Montgomery unable to start against the Lancers do to an injury, Chaffee managed only 83 yards through the air and 222 overall as the Lancers won in double overtime.
"We threw for 342 yards last week with my quarterback and he ran for another 60," Chaffee coach Charlie Vickery said of last week's contest. "But that's no excuse, we just didn't play as well tonight. We [knew] what was coming on that last play right when they scored the touchdown.
"We still had opportunities, we just couldn't get anything going. It's not good weather for a shotgun offense, obviously."
St. Pius took over after a penalty on its own 19-yard line and slowly started to push in to Red Devil territory. Almost three minutes expired before the Lancers pushed past midfield and, after a sack on the Red Devils 42-yard line, St. Pius was forced to call its final timeout.
Senior Talon Cook ran the ball up the left sideline on the next play before turning toward the middle of the field to escape a pair of defenders near the goal line.
By the end of his run Cook had gone 42 yards to tie the game 8-8 with 1 minute, 2 seconds left in regulation.
"We had a kid who had played offense for us pretty much the last couple of years," St. Pius head coach Jerry Woods said of Cook. "He got a little dinged up, so he was only playing defense.
"His legs were fresh for that drive and he was ready to roll. We threw him out there, ran a couple inside reverses with him. It worked great."
The Red Devils blocked the point-after attempt to send the game into overtime.
While the Lancers turned to Cook late in the fourth, they relied on junior Chris Filer to do the heavy lifting in overtime. After both teams went scoreless in their first possessions, St. Pius started the second overtime with a couple short plays before Filer broke off a 13-yard run up the middle to 5-yard line.
The Lancers again handed off the Filer on the next play. He barreled up the middle and into the end zone for the go-ahead score. Filer got the ball again on the two-point conversion and put his team up 16-8.
"I think they wore us down a little bit," Vickery said. "We're not very deep at all, and they wore us down a little.
"Our defense played well most of the night. Can't fault their effort at all."
Chaffee quarterback Jimmy Golden connected with Devon Yahn for 14 yards early in its ensuing drive, but the Red Devils soon found themselves facing third-and-11. Golden's pass to the left corner of the end zone was intercepted by freshman cornerback Tryson Thorton.
The Red Devils relied on their special teams to put the Lancers in an early hole after St. Pius was forced to punt on its opening drive.
Chaffee junior Travis Hall grabbed the kick on a hop and took off down the right sideline. He sprinted 60 yards to give his team a 6-0 advantage just two minutes into the game.
The Red Devils led 8-0 at halftime after they blocked a Lancer punt in the end zone with 3:09 left in the second quarter.
St. Pius didn't put its first point on the board until a snap on a Red Devil punt late in third quarter sailed over the punter's head and out the back of the end zone for a safety.
St. Pius 16, Chaffee 8
C -- Travis Hall 60 punt return (kick failed), 10:01
C -- Safety, 3:09
S -- Safety, 1:21
S -- Talon Cook 42 run (kick failed), 1:02
S -- Chris Filer 5 run (run good)
RUSHING -- St. Pius, Lance Ervin 7-13, Chris Filer 18-104, Tryson Thorton 1-4, Mickey Karoly 8-45, Brendan Withrow 1-7, Talon Cook 5-71; Chaffee, Jimmy Golden 28-75, Charlie Montgomery 3-12, Layton Tinkhoff 2-42, Devon Yahn 1-2, Cole Hanna 1-5, Thomas Robbins 1-3.
Passing -- St. Pius, Mickey Karoly 7-20-61; Chaffee, Jimmy Golden 8-19-83.
Receiving -- St. Pius, Isaiah Hennessey 3-18, Tryson Thorton 4-43; Chaffee, Devon Yahn 5-46, Layton Tinkhoff 3-37.