Week 9 of the high school football season marks the final challenge for many teams, but the prelude to the playoffs for others.

Brewer Witches (8-0) vs. Winslow Black Raiders (6-2), 1:30 p.m. Saturday, Poulin Field, Winslow: Brewer seeks to cap off an undefeated regular season but faces a sturdy test against a Winslow team that has averaged 41.7 points during its three-game winning streak.

Brewer has been the PTC Class B’s most balanced team, blending a high-octane offense with a defense that has posted five shutouts, including last week’s 13-0 quieting of Leavitt of Turner Center. That defense is led by the athletic linebacking corps of Chad Szylvian, Jake Richter, Zack Wilson and Ben Caldwell.

“They set the tone defensively with their hard work and hustle,” said Brewer coach Ed Ortego. “We’ve got some real quick kids on defense. We don’t have a lot of size, but the size we have is in the right spots on the defensive line.”

Winslow’s late-season offensive surge has been led by sophomore quarterback Steven Siviski, the brotherly running back tandem of Justin and Ryan Lindie, and senior wideout Eric Lopez.

“Winslow is very quick and very explosive,” Ortego said. “We think this is a very good matchup.”

Brewer is on track to have the No. 1 seed throughout the Eastern B playoffs that begin next week, while Winslow, Belfast and Leavitt currently own the other three postseason berths. Leavitt (5-3) has a major crossover test Friday night at 7-1 Mountain Valley of Rumford, while 5-3 Belfast plays host to 0-8 Mount Desert Island in its regular-season finale Friday night.

Orono Red Riots (7-1) vs. Bucksport Golden Bucks (8-0), 7 p.m. Friday, Carmichael Field, Bucksport: Bucksport is in quest of its first undefeated regular season since 1983 against a resurgent Orono team that has won its last six games.

“[Orono’s] players believe in what they’re doing,” said Bucksport coach Joel Sankey. “We know they like to control the football. They have very good backs and are very quick, and they do a good job of faking with the football.”

Sankey and Orono’s Bob Sinclair are longtime coaching comrades, both at Bucksport High and in the 1999 Maine Shrine Lobster Bowl, when Sinclair was the East head coach and Sankey the offensive coordinator.

Both teams have explosive running games featuring 1,700-yard rusher Nick Tymoczko of Bucksport and Orono’s Mardy Simon, who topped 1,000 yards last weekend and is leading the Red Riots to their first playoff appearance since 1997.

“What we have to do is find a way to slow down Tymoczko and [John] Harvey in the run game and be very wary of [quarterback] Joey Carmichael, who can throw the ball,” said Sinclair. “We need to do that and minimize mistakes.”

Bucksport, Foxcroft Academy, Orono and Mattanawcook Academy of Lincoln already have clinched LTC Class C playoff berths, with Mattanawcook locked in as the No. 4 seed.

Bucksport will clinch the No. 1 seed with a victory against Orono, but wins by Orono on Friday and 7-1 Foxcroft Academy at 3-5 Dexter on Saturday would create a three-way tie for the conference lead. With all other tiebreakers being equal, seedings would be determined by the combination of a coin flip and head-to-head results, according to LTC statistician Mike Archer.