Home-field advantage hasn’t been advantageous for Manteca High’s football team the last two years.

The Buffaloes dropped their first-round losses to lower-seeded teams in both instances, more recently to Vanden 55-22 in an upset involving No. 1- and 16-seeded teams. In 2009 they led 28-3 in the third quarter before falling to No. 9 Casa Roble, 35-28.

On Friday, No. 3 Manteca (9-1) hosts No. 14 Cosumnes Oaks (7-3) to open the Sac-Joaquin Section Division-III playoffs. Also Friday, No. 6 Ripon (8-2) takes on No. 11 Livingston (5-5) in Division IV, and on Saturday Ripon Christian (6-4) plays host to Rite of Passage/Sierra Ridge (5-5) in Division VI.

“I have challenged our guys this week,” Manteca coach Eric Reis said. “We have not done it in Week 11 the last couple of years, so let it be your class that gets this thing going again.”

Mother Nature could be useful Friday should it rain. A sloppy surface would help Manteca keep up with the speedy athletes of Cosumnes Oaks, a first-time postseason qualifier.

“One thing I noticed on film is that they played a lot on FieldTurf,” Reis said. “They even asked us what kind of artificial turf we play on. It could get real muddy if it rains.”

Reis compares the Wolf Pack to Stockton’s Edison and Stagg — teams Manteca faced in non-league — in style of play and athletic ability.

Quarterback Andrew Williams is a classic dual threat out of the spread offense, throwing for 778 yards and nine touchdowns. Most of his damage is done on the ground, where he has rushed for a team-best 930 yards and 11 scores.

“Their quarterback can throw the haymaker,” Reis said. “He throws it 40-50 yards deep very accurately.”

Running back Tavon Willis (734 yards, 11 TDs) and 6-foot-4 receiver Michael Thomas (28 receptions, 383 yards, seven TDs) are also dangerous. Cornerback Marcus Rios, who was offered a scholarship by Boise State, heads the defense.

“We need to make sure we limit turnovers,” Reis said. “We had four turnovers last week, and you cannot do that in the playoffs. We have to protect the football and keep their offense off the field.”

Manteca and Cosumnes Oaks share two common opponents (Kimball, Galt) with each beating both. The Pack ended the regular season against the Sierra Valley Conference co-champions, first beating Vista del Lago 34-21 and losing to Liberty Ranch, 28-15.

Ripon’s first-round opponent is also coming off a tough stretch. Livingston’s hot 5-1 start ended up being huge, because it went on a four-game losing streak before sneaking into the postseason. That skid included losses to the Western Athletic Conference’s top squads (Patterson, Central Catholic, Los Banos) and a stunning 37-20 defeat to Ceres.

The Wolves do own an impressive 41-34 victory over Modesto Christian, which lost to Ripon by the same margin, 40-33, in Trans-Valley League play.

Livingston’s power running game is led by Brian Perez (709 yards, eight TDs) and Adrian Muniz (669, 8). Perez is also the team’s leading tackler with 77, and fellow linebacker Juan Zuniga has 7 ½ sacks.

Ripon Christian’s challenge this week is getting to know Rite of Passage/Sierra Ridge of San Andreas with little information about the Rams available on the internet.

“They didn’t have much for game film either,” Ripon Christian coach John Vander Schaaf said.

The Knights do know that they have to keep an eye on freshman Karon Scott, who blew up for 346 yards and four touchdowns in a 36-35 Central California Athletic Alliance win over Big Valley Christian.

Ripon Christian, by the way, trounced BVC 40-0 in its season opener. Rite of Passage/Sierra Ridge was the runner-up to undefeated Millennium in league, but RC is arguably the toughest opponent it will face this season.

Ripon Christian is riding a four-game winning streak and has recovered from its early-season rash of injuries. Both teams are in the playoffs for the second time and are looking to earn their first postseason victory.

“We’re just going to go out and play our game,” Vander Schaaf said. “We know what we want to do and what we can do.”