City rivals Manteca High and Sierra could lock up in the second-round of the Sac-Joaquin Section Division III playoffs if they get by two Sacramento schools they have never previously faced.

A win for Ripon High would lead to an expected matchup with powerhouse Central Catholic in Division IV.

And Ripon Christian is set up for a two-hour trek to meet the top seed in Division VI in the semifinals but has a real shot at adding to its already-historic season.

The Manteca area’s four remaining teams kick off the postseason at 7 Friday night. The section released the brackets Saturday afternoon via the Internet (www.cifsacjoaquin.tv) with PlayOn! Sports broadcasting a special playoff preview show.

Manteca (6-4) will be the only team travelling, as it heads to Sacramento to square off with No. 6 Inderkum (8-2). Third-seeded Sierra, meanwhile, takes on No. 14 Rosemont (6-4). Both Inderkum and Rosemont are new schools from Sacramento that played their first varsity games in 2005, and both have enjoyed immediate success.

Undefeated Ripon is third in Division IV and entertains No. 14 Amador (7-3). Ripon Christian (8-2), No. 4 in the small-schools bracket, welcomes No. 5 Elliot Christian (7-3) of Lodi. The Knights typically hold their home games at neighboring Ripon’s Stouffer Field but will play at Modesto Christian Friday.

Division III

Top-seeded Oakdale (9-1) is a heavy favorite to at least reach the final round for a third straight season. The reigning two-time champ, Del Oro, is now in Division II. Yuba City and Placer were two teams projected to rank highly in this bracket, but Yuba City moved up to Division II while Placer dropped down to IV.

Fifth-seeded Cosumnes Oaks (8-2) has a 10-point win over No. 7 Sacramento but lost to No. 2 Vista del Lago (9-1) 35-34 in a Sierra Valley Conference game. The Wolfpack from Elk Grove is considered a likely semifinal opponent for Oakdale.

Inderkum looms as a darkhorse contender to win it all. The Tigers have some impressive wins under their belt and have qualified for the postseason seven straight years with two final-round appearances under longtime head coach Terry Stark.

Manteca is playing its best ball of late, and an upset over Inderkum would stage a quarterfinal showdown with Sierra, which won their Week 6 contest, 35-26. Sierra boasts one of the most explosive offenses in the division and may need to ride its attack to mount a deep run.

Division IV

Lauded as one of two power divisions (II being the other) in this year’s SJS playoffs, Division IV consists of three 10-0 teams, three that are 9-1 and six more check in at 8-2. The Trans-Valley League has five representatives in the bracket, and no other conference in the section has as many qualifiers.

Most anticipate a rematch of top-seeded Placer (10-0) and No. 6 Central Catholic (8-2) — the undefeated Hillmen made a statement with their 48-30 win at Central in the season opener. Both teams, however, must go through a gauntlet of tradition-rich programs to make it happen.

Placer may need to face both SJS Division-IV finalists from 2011 as it kicks off with No. 16 Hilmar (6-4). Escalon (8-2), which was upset by TVL rival Hilmar in last year’s title round, hosts Calaveras in an intriguing matchup No. 8-9 seeds. Los Banos (9-1), seeded fifth, might have an easier path to the semifinals.

Then there’s No. 2 Argonaut and No. 3 Ripon, the other 10-0 squads. Tenth-seeded Center (8-2) lost the Pioneer Valley League championship to Placer 15-14 in Week 10 and could prevail as a surprise finalist.

Division VI

Ripon Christian’s placement as the No. 4 seed seems unfair at first glance. The Knights upset Division V favorite Le Grand last week to earn a three-way share of the Southern League title, and their opponents’ win total — the second tiebreaker behind head-to-head result — is better than second-seeded Brookside Christian’s (8-2).

Problem: three teams in the field of six hail from the Central California Athletic Conference, and the section avoids first-round contests between league rivals. That ends up bumping RC out of the preferred second spot, which comes with a first-round bye and semifinal home game.

Instead, the Knights are to face Elliot Christian, a team is beat 28-13 in nonleague play. Win Friday, and they are rewarded with a 114-mile trip up to Foresthill (9-1). Third-seeded Woodland Christian (8-2) and No. 6 Big Valley Christian (5-5) meet in the other opener.

Ripon Christian has a legitimate chance to earn its first-ever section title. Its resume is more impressive than that of Foresthill’s, which has faced only one opponent (Woodland Christian twice) with more than three wins. Brookside of Stockton is just two years removed from playing in a CIF State Bowl Game.