The 2005 season was one to remember.  The Red Sox assigned many top prospects to Portland, the Sea Dogs hosted the Eastern League All-Star game, and the team reached the playoffs for the first time in eight years.

The opening-day roster included Hanley Ramierez, Dustin Pedroia, Brandon Moss, David Murphy, Jon Lester, Manny Delcarmen, Cla Meredith and Jonathan Papelbon. Under first-year manager Todd Claus, the team began the season with 10 straight wins. Meredith started strong with nine saves in 15 scoreless innings before eventually being promoted to the Red Sox.

On July 11, Lester fired a complete-game one-hit shutout against New Hampshire where he struck out a franchise-record 13 batters.  Lester would go on to finish the season with an 11-6 record and league bests for ERA (2.61) and strikeouts (163).

On July 13, the Eastern League All-Stars descended on Hadlock Field. Sea Dog Kenny Perez broke a 6-6 tie in the eighth inning with a game-winning two-run double.

David Murphy batted .310 in his final 66 games, including a .379 average in 28 games in July after hitting just .240 in his first 69 games. He finished with a .279 average, 14 home runs and 75 RBI.

In August, the Sea Dogs received a boost when reliever and 2005 first-round draft pick Craig Hansen joined the club. In 11 games with Portland, he did not allow a single run to score.  Catcher-turned-pitcher Edgar Martinez posted a 1.89 ERA between Class A Wilmington and Portland.

The Sea Dogs ended the regular season with a 76-66 record, capturing their fourth division title, and faced Trenton. Chad Spann set the tone in Game 1 with ninth-inning grand slam off the Citgo sign for a dramatic 5-3 win. Portland would go on to defeat Trenton 3-2 and face Akron for the championship. 

In the finals, Portland took the first game but the Aeros went on to win the next three to secure the championship.