One week of girls lacrosse playoffs are in the books in Nassau County, leaving four teams in each class to battle it out for the county crowns. As expected, the defending champions and runners-up are still alive and favored for their next matchups. But don’t count out upsets. Last round, three lower seeds advanced.

Each class comes with intrigue. Class A pits two upstarts against two powers. Baldwin and Port Washington have passed every test put in front of them, but have yet to play against the likes of Massapequa and Farmingdale.

Class B might have the largest collection of talent evidenced by No. 5 Plainedge defeating Conference I’s Calhoun for the second time this season, not to mention the powers of Wantagh and Garden City sitting at the top.

And Class C probably has the best first round matchup as Cold Spring Harbor and North Shore continue what has been an epic rivalry for the past two seasons.

Here’s what to expect this week at Denton Ave.:

Class A, Tuesday:

No. 1 Farmingdale (10-4) vs. No. 5 Port Washington (15-0-1) 4 p.m.: The season after has been different for Farmingdale, which ended the season 5-4 in its last nine games, after going undefeated last year. But that record is deceiving. In all three of the four losses, to Garden City, Manhasset and St. Anthony’s, all nationally-ranked teams, the result could just as easily have been flipped. Farmingdale is still extremely dangerous.

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So is Port Washington. Thanks in large part to the Froccaro cousins, the Vikings went 15-0-1 this season, the tie coming in a darkness-shortened game against Baldwin. Playing a Conference III schedule relegated them to the No. 5 seed, but Port Washington is the strongest lower seed Class A has had in years. We’ll find out Tuesday whether they’re ready to challenge Farmingdale or if they’re still a year away.

No. 2 Massapequa (6-9) vs. No 6. Baldwin (11-3-1) 6 p.m.: A rebuilding year for Massapequa still means a No. 2 seed. The Chiefs ended the regular season with three-straight losses, but late-season wins over Sacred Heart and South Side showed they’re still capable of beating playoff-caliber teams. Massapequa and Farmingdale have met in every Class A playoff final since it was switched to its current incarnation.

Baldwin lost only three times this season and knocked off third-seeded Hicksville in overtime to get this far. Led by Allie Rodgers, one of LI’s leading scorers, and Shakoya Smith, who scored the game-winner against Hicksville, Baldwin could be a dangerous six seed.

Class B, Wednesday:

No. 1 Garden City (16-0) vs. No. 5 Plainedge (11-5) 6 p.m.: If Garden City wins a fifth straight state title, the Trojans should be national champs. When you win Nassau Conference I and a New York state title, not to mention non-league victories over Shoreham-Wading River, Darien (Conn.), Mt. Hebron (Md.) and South River (Md.) that status is deserved. But before that, Garden City must get past a Plainedge team that has already pulled an upset. The Trojans started the playoffs with an 18-2 victory over Jericho.

Plainedge tied with Mineola at the top of Conference II with a 7-1 record. It’s the Red Devils' two victories over Calhoun and its win over Mineola that show the kind of damage they can do against playoff teams. Kim Kovar scored 46 goals this year to lead Plainedge, which hasn’t lost since April.

No. 3 South Side (6-9) vs. No. 2 Wantagh (11-4) 4 p.m.: Wantagh took a step closer to the national elite this year, leaving its biggest mark during a 23-15 rout of Farmingdale on May 6. Few teams can score like Wantagh, which has Paula Schmidt and Jackie Sileo ranked among the island’s leading scorers. Despite the great regular season, it still likely the season once again will likely hinge on a showdown with Garden City.

South Side had a rough introduction to Conference I, winning only one league game, over Calhoun two weeks ago. But the Cyclones were competitive in close losses to North Shore, Cold Spring Harbor and Massapequa and head into the playoffs battle-tested. Wantagh won 17-6 during the regular season.

Class C, Thursday:

No. 1 Manhasset (14-1) vs. No. 4 Mineola (12-4) 4 p.m.

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Manhasset lost only once during the regular season, to Conference I champion Garden City. Aside from that game, Farmingdale was the only Long Island team to come within five points of the Indians. Few teams can match the offensive firepower of Manhasset. Rotating goalies Grace Morelli and Jen Levy add another layer to the team.

Mineola won Conference III last year and had no trouble with Conference II, going 7-1 and winning a share of the Conference title. This is a team on the rise. With a multitude of scorers, it seemed someone was breaking a school record every week. Mineola defeated a tough Friends Academy team 15-11 in the quarterfinals.

No. 2 North Shore (10-5) vs. No. 3 Cold Spring Harbor (9-6) 6 p.m.: They saved the best quarterfinal for last. North Shore won at Cold Spring Harbor 12-11 in overtime during the regular season, to earn the No. 2 seed and ensure that they’ll wear home jerseys for this one, though this one will be played on a neutral site. Last season these two teams split with CSH winning in the regular season and North Shore winning in the Class C semifinals. North Shore’s been to the last two straight county finals.