Israel Mcclain (28) and the Westfield defense have hit their playoff stride, which could signal trouble for the South Lakes offense. (John McDonnell/The Washington Post)

No. 5 South Lakes (12-1) at No. 10 Westfield (11-2)

What: Virginia 6A North region final

When: Saturday, 2 p.m., Where: Westfield High School, Chantilly

Tickets: $10

How they got here: South Lakes upset top-seeded Lake Braddock, 40-22, behind the headsy play and gutsy rushing of quarterback Devin Miles, who ran for two touchdowns. The Seahawks defense also held star tailback Lamont Atkins to 17 yards on 12 carries and returned an interception for a touchdown. Westfield, the defending Virginia 6A state champion, rode its defense to a 31-13 win over Madison. The Bulldogs returned a kick and interception for a touchdown and forced three turnovers.

When South Lakes has the ball: The Seahawks showcase a unique, up-tempo, power offense. They want to catch defenses off balance, then run between the tackles and use zone-read running schemes for misdirection. Albert Mensah (1,227 yards, 23 touchdowns) is the every down back that keeps the South Lakes offense in reasonable down and distances. Spencer Alston (932 yards, 20 touchdowns) is the playmaker in the backfield who likes to get outside. Watch for slot receiver Andrew Funaki, Miles’ favorite target in the passing game, to have an impact before the game is over. But Westfield’s defense is its bread and butter, and the unit the Bulldogs rode all the way to the 6A state championship last December was in playoff form last week against Madison.

When Westfield has the ball: The Bulldogs’ offense is the team’s weakest link, but it hasn’t hurt them so far in the playoffs. Quarterback Rehman Johnson has a big arm and is a capable runner, but has struggled against good defenses to find athletic receivers Sean Eckert and Ivory Frimpong. Nathanael Chung and Eugene Asante split carries for a running game that managed only 68 yards against Madison. Still, Westfield has big-play potential and the region’s most lethal kicker in Virginia commit and Under Armour All-American Brian Delaney on its side.

Skinny: South Lakes is the more balanced team with an offense that has won shootouts when necessary and a defense that has shut down dangerous offenses. But Westfield’s defense might be overwhelmingly good. Since the playoffs began, the Bulldogs are allowing 7.6 points per game. If South Lakes can keep its offense churning, however, Westfield may struggle to keep pace.