BANGOR – There’s a two-time defending state champion, another reigning regional titlist, and six other teams that would like to fill those championship baseball cleats.

All have endured the challenges of regular-season play to reach the Eastern Maine finals, to be contested Tuesday and Wednesday at Mansfield Stadium.

Tuesday’s doubleheader begins at 3 p.m. with the Class B clash between Mount Desert Island of Bar Harbor and Maine Central Institute of Pittsfield, followed at 7 p.m. by the Class D matchup between Lee Academy and Deer Isle-Stonington.

The Class A title game between Oxford Hills of South Paris and Edward Little of Auburn is set for 3 p.m. Wednesday, followed at 7 p.m. by the Class C rematch between George Stevens Academy of Blue Hill and Searsport.

The winners advance to Saturday’s state championship games, with the A and C contests to be held at Mansfield Stadium, and the B and D games to be played at Saint Joseph’s College in Standish.

Here’s a chronological look at the Eastern Maine finals:

Class B, No. 10 MCI (11-8) vs. No. 5 MDI (11-6): These two teams are seeking their first regional title, with MDI in the final for the first time since 1988 and MCI believed to be making its first appearance ever in the EM championship, according to Huskies coach Phil Hendricks.

MDI jumped to the top of the Class B charts at midseason with a win over Class A Hampden Academy, then slumped a bit before regaining form near the end of the regular season. Coach Mike Clark’s Trojans are led by senior righthander Andy Pooler, the ace of the pitching staff and a .521 hitter with 14 RBIs.

First baseman Marcus Maffucci, another of the six seniors figuring prominently in MDI’s success, is batting .481 with 26 RBIs.

MCI rebounded from an 0-4 start to make its way to Mansfield. The Huskies were hurt early in the season by injuries to righthanded pitchers Phil Hendricks – the coach’s son – and Andrew deBerthune. Both are healthy now with deBerthune, a junior, expected to start against MDI.

The Huskies have been solid defensively, averaging just over one error per game, and boast a balanced offense keyed by senior shortstop Marty Quint, senior second baseman Ryan Kennedy, Hendricks and sophomore catcher Victor Quint.

Class D, No. 5 Lee Academy (15-3) vs. No. 3 Deer Isle-Stonington (13-3): Lee graduated just three seniors from its 2004 EM championship team, and boasts a strong nucleus led by junior shortstop Tyler Thompson and senior righthander Gerry Worster. Thompson leads the team in hits, runs, extra-base hits and RBIs, while Worster is 5-2 on the mound.

Coach Dave Hainer’s club also benefits from a strong schedule – the Pandas play an all-Class C regular-season schedule except for games against Class D Katahdin of Stacyville and Bangor Christian.

Deer Isle-Stonington reached the EM semifinals a year ago before being ousted by Lee, and that Mariners team played five freshmen. That quintet are now sophomores and, while coach Darren Eaton’s club is still young, that added experience has paid dividends.

Deer Isle-Stonington is the only team to defeat Searsport this year, and also played solidly against the other Class C finalist, George Stevens.

The Mariners, which reached the EM final in 2000 but are seeking their first championship, are led by senior outfielder-pitcher Nick Ciomei, one of four seniors.

Class A, No. 5 Edward Little (14-5) vs. No. 2 Oxford Hills (15-3): Edward Little knocked off top-seeded Gardiner 3-1 in the semifinals behind the pitching of junior Chris Merrill.

Coach Scott Annear’s Red Eddies, seeking their first regional title since winning the Class A state championship in 1992, have won 11 of their last 14 games since a 2-2 start. One of those wins was an 8-5 decision against Oxford Hills on May 28, a game also pitched by Merrill.

Justin Ciszewski swings a productive bat in the middle of the Red Eddies’ lineup.

Oxford Hills is seeking its first EM title since 2002, and has been one of the KVAC’s top programs in recent years. Coach Shane Slicer’s Vikings were on the brink of elimination in their quarterfinal against Skowhegan, but rallied from a 5-1 seventh-inning deficit to win in extra innings.

OH then eliminated Bangor in the semifinals behind the senior righthander Matt McDonnell. Corey Saunders is another quality pitcher for the Vikings, while McDonnell, Chris Jennings, Kyle Keniston and Kelvin DeCato pace the offense.

Class C, No. 2 Searsport (15-1) vs. No. 1 George Stevens Academy (14-4): GSA, the two-time defending state champion, is seeking its fourth straight EM title. But Searsport likely won’t be intimidated – the Vikings lost a one-run decision to the Eagles in last year’s final and already have defeated GSA twice this spring.

GSA features two talented, veteran lefthanders in senior Dan Hilts and junior Collin Henry. Henry also figures prominently in the offense for coach Dan Kane’s club, as do table-setters Blake Wessel and Phineas Peake and freshman catcher Lucas Marks.

Searsport also has solid recent baseball tradition. In addition to last year’s run to the EM final, the Vikings won the Eastern Maine championship as recently as 1999.

Searsport relies heavily on defense and pitching, in particular the work of Nickerson (6-0, one earned run allowed) on the mound. Nickerson pitched a six-hitter in the Vikings’ 3-1 win against GSA on May 2, and tossed a one-hitter in the rematch, a 4-1 win on May 20.

Coach Dave Pepin’s Vikings graduated six starters from last year’s team, but boast some quality veteran leadership in outfielder Mike Adams and middle infielder Ryan Shute.