An Archbishop Wood defense that was victimized by big plays earlier in the season seems to have turned the corner.

Last Friday, in a 36-6 romp over Allentown Central Catholic, the first-teamers held prolific rusher Colin McDermott and company scoreless in the first half and then rested in the second. A week earlier, the unit muffled Interboro's running attack in a 35-7 triumph.

John Berthcsi, a sure tackler and fiery leader, has played a key role in the Vikings' marked improvement.

"He literally grew up from being a boy to a man in the last three years," said Mike Carey, Wood's assistant head coach and defensive coordinator.

Friday, with Berthcsi at strong safety, the Vikings (12-2) will try for their second straight PIAA Class AAA state title against Erie's Cathedral Prep. The matchup is set for 7 p.m. at HersheyPark Stadium.

"They have a lot of good athletes, a ton of guys who can make plays," Berthcsi said. "For us to do well, everybody has to do his job. We have to play assignment football."

Berthcsi, a senior, was slowed by injuries the last two seasons. Last year, the 5-foot-10, 185-pounder tore a ligament in his right ankle in Week 5. A broken left arm midway through the 2010 season spelled the end of his sophomore campaign.

"I try not to think about what happened in the past," Berthcsi said. "I just go out and play hard. You can't worry about possibly being injured."

Wood's coaches recognize the squad's top defensive performer after each game. Berthcsi was tabbed "The Viking" for his efforts in consecutive wins last month over Cardinal O'Hara, Bonner-Prendergast, and Bok. He also gained the honor another time.

In Week 8 this year, Berthcsi, who played youth football for the Northampton Indians, was held out of the starting lineup.

"I wasn't making plays, and I let a few interceptions get away," he said. "It definitely motivated me to get my stuff together and get back on track."

Berthcsi, a midfielder in lacrosse, is joined in the secondary by cornerbacks Anthony Roakes and D.J. Brinkley and free safety Kendall Singleton.

Up front, the charge is led by tackles Jake Cooper and Shane Neher, and ends Josh Messina and Tyler Smith. The linebackers are Andrew Guckin, an 1,800-yard rusher; Nick Arcidiacono; and Benji Abercrombie.

"Early on, we weren't playing together," Berthcsi said. "Everybody was kind of doing their own thing. We're playing as a team now."

Cathedral Prep, of District 10, is averaging 48.4 points. In a spread scheme, quarterback Damion Terry, a 6-4, 210-pounder ticketed for Michigan State, has thrown for 3,282 yards and 48 touchdowns.

The Ramblers also are sparked by halfback Delton Williams (663 yards rushing yards; 56 catches for 785 yards and 10 TDs). Wideouts Alex Greenwalt (41 catches for 633 yards) and Jake DeHart (31 for 399) have combined for 10 scores.

Last year, Wood, with six Division I-A recruits, went 14-1 en route to its first state crown.

"We're looking to make our own story," Berthcsi said. "We're excited about the challenge."

Familiar foe. Friday will mark the fourth time Carey has coached against Cathedral Prep.

With Carey in charge at Central Bucks West in 2000, the Bucks fell to the Ramblers, 41-35, in overtime. The loss snapped a 59-game winning streak and three-year Class AAAA championship run.

"It's absolutely the worst defeat of my career," said Carey, who was Mike Pettine's right-hand man during C.B. West's dynasty days. "It was my first year as a head coach, and I loved those kids. It was a great group to coach."

In 1991, the Bucks captured their first PIAA state title with a 26-14 win over Cathedral Prep at Mansion Park Stadium in Altoona. In 1999, boosted by Andrew Elsing's punt block, they nipped the Ramblers, 14-13, in Hershey.

Contact Rick O'Brien at robrien@phillynews.com, or @ozoneinq on Twitter. Read his blog, "The O'Zone," at www.philly.com/ozone