The stunned silence of the North Penn fans as Ridley erupted in celebration after its 19-10 upset Friday night in the PIAA Class AAAA state quarterfinals may have been similar to how other football fans reacted to Ridley's victory.

There may not have been too many people outside Ridley who predicted the Green Raiders would knock off No. 1-ranked North Penn and advance to Saturday's semifinal against La Salle.

But don't tell that to the teams that have had the unfortunate task of playing against Ridley this season.

"I wasn't surprised at all when Ridley won," said Garnet Valley head coach Mike Ricci, whose team handed Ridley its only loss this season in a 20-14 victory that Ricci described as a great high school football game that could have gone either way.

"Ridley is a great team. Their defense is great. They do a great job of running the ball, and I think they're a lot quicker than people think. Ridley is the type of team that whatever you do well, they'll take it away from you."

Ricci might not have been surprised, but, according to the stat sheets this season, "shocking" might even be an understatement when trying to sum up Ridley's victory over the Knights.

Not only was Ridley (13-1) the first team to beat North Penn (14-1) this season, but when Alex Nicolino crossed the goal line after a 93-yard kickoff return late in the first half, he gave Ridley the distinction of being only the second team this season to take a lead on the Knights.

North Penn had not trailed in a game since the first half of its first game of the season, a game it went on to win, 42-10, over Bethlehem Liberty.

But Nicolino's touchdown, which put Ridley ahead, 13-10, going into the half, did more than just give his team the most first-half points scored against North Penn this season. It was the spark that lit a historic upset, and it gave the Green Raiders enough momentum to carry into Saturday night's semifinal game against La Salle.

As impressive as Ridley's offense was in the win - only Neshaminy put up more points against North Penn this season in a 35-22 loss to the Knights on Nov. 20 - the win would not have happened with anything less than a heroic performance by the Green Raiders' defense.

The total of 10 points was by far the lowest number of points North Penn scored this season. Before Friday, North Penn's lowest point total was 27, which it recorded twice in wins over Souderton and Central Bucks South.

This win "was a testament to our kids on defense," Ridley head coach Dennis Decker said after the game.

Ridley's defense didn't just hold a North Penn offense that averages 36.5 points per game in check. Every time the Knights found themselves with a chance to mount a comeback, they were met with a veritable brick wall formed by the Ridley defense.

Ridley linebacker Sam Dixon-Dugan, who stuffed North Penn running back Craig Needhammer on a fourth-and-1 play from the Ridley 6-yard line early in the third quarter, led his defense against North Penn and will have his hands just as full Saturday night against La Salle.

La Salle (12-1) enters the game averaging 30.8 points per game. As was the case with North Penn, not many teams have found an answer to La Salle's offense. The Explorers scored more than 30 points seven times this season.

Like Ridley, La Salle wasn't supposed to be playing football this weekend. But with their 17-14 win over Easton on Saturday, the Explorers became the first team in the six-year history of District 12 to advance to the semifinal round of the state tournament.

But that's not to say the Explorers didn't show that they deserve to be where they are throughout this season. The only blemish on La Salle's record this year came when it lost to St. Joseph's Prep, 24-17, on Sept. 26.

The Explorers came back to beat the Hawks, 35-28, for the Catholic League Championship on Nov. 20.

"I wasn't surprised that La Salle won," said Cardinal O'Hara coach Dan Algeo, who lost twice to the Explorers. "Offensively, they have a lot of weapons. And defensively, they're a very good team. But I don't think people fully give them credit for their special teams. Their special teams are tremendous, and it's such an important part of the game."

The vaunted Ridley linebacker corps of Dixon-Dugan and Casey Decker will have to stop La Salle all-purpose running back Jamal Abdur-Rahman, who in the last two games led a La Salle offense known for its passing attack.

"This is probably the most physical team they've had," Algeo said. "Everybody thinks they're this pass-happy team and that they're all finesse. But they're one of the toughest, most physical teams we played."

Another crucial aspect of Saturday's game will be how Ridley cornerbacks Dion Shaw and Nicolino respond to the combination of La Salle quarterback Drew Loughery and wide receivers Sam Feleccia, Connor Hoffman and Kevin Forster.

Forster was also ranked sixth this week in The Inquirer's list of the top safeties in Southeastern Pennsylvania. He played a major role in La Salle's ability to keep Easton to just 131 all-purpose yards through the final 41 minutes of Saturday's game.

"When we're going on defense, we're real confident about what we can do," La Salle end Steve Sinnott said after beating Easton. "We don't have the biggest or fastest players, but when we play as a unit, it's hard to gain yards on us."

Forster and the La Salle secondary are up against a much tougher passing attack this weekend. Ridley quarterback Colin Masterson has seven postseason touchdown passes, and he has three dangerous receivers in Nicolino, Dion Shaw, and Norm Donkin.

"I expect it to be a good game," Algeo said. "These teams are both traditionally tough as nails. All the teams playing now are good, so it should be a good game."