PORTLAND — The Portland Sea Dogs boasted five of the Boston Red Sox’s top 20 minor league prospects in their starting lineup for Thursday night’s home opener, but it wasn’t enough — at least on this night.

Damon Sublett belted a two-run home run in the 11th inning to give the Trenton Thunder a 4-2 win over Portland before the remnants of 5,654 fans at Hadlock Field in the Sea Dogs’ 17th home opener.

Sublett, who had been hitless in his four previous at bats, lifted a 1-1 mistake from Portland reliever Ryne Lawson over the fence in left-center.

“It was a fastball that he left up over the plate and I just tried to put a good swing on it and luckily I did,” said the Thunder’s 24-year-old outfielder. “Early on, we had a chance to break the game open and we never did, but luckily we came out with the win anyway.”

Sublett’s homer broke up what had been an impressive bullpen duel. Prior to the 11th, four relievers combined for nine innings of scoreless, three-hit relief between the two clubs.

“It was a good ball game. They got the big hit late,” Portland manager Arnie Beyeler said.

Shortstop Julio Iglesias, a free agent signing from Cuba ranked ninth in Boston’s organization, had two hits, including a double, and scored a run in his Hadlock debut. First baseman Lars Anderson, who was ranked No. 1 last year but dropped to fourth this year after a disappointing 2009 season with Portland, had a double and scored a run.

Both starters had their moments, too. Portland (4-4) starter Kyle Weiland fanned five his first time through the Thunder (6-2) lineup. He also made what might stand up as the Sea Dogs’ defensive play of the year when Reid Gorecki popped up a bunt to lead off the second. Weiland sprinted off the mound and dove across the base path on the third base side to make the catch in foul territory.

“It was just one of those things you react to. You don’t have too much time to think about it,” Weiland said. “I just saw it get in the air, so I broke towards third base. I didn’t plan to leave my feet or anything. It just kind of happened. I got up and was like ‘All right, free out.’ I got a little muddy and it knocked the air out of me.”

Weiland issued a leadoff walk to Justin Snyder which led to the game’s first run in the third. Austin Romine, son of former Red Sox outfielder Kevin Romine, doubled home Snyder and the Thunder started to go after the Portland right-hander.

“He was getting ahead in the count a lot and we got a little aggressive with him the second time through,” Sublett said. “Luckily, he came out pretty early in the game. I’m sure he’s on a pitch count.”

Trenton doubled the lead in the fifth but Weiland (5 innings, two earned runs, four hits, three walks, six Ks) was fortunate to escape further damage when, with the bases loaded and none out, Snyder took too wide of a turn at third on a grounder to second and was thrown out at third by an alert Iglesias after a runner was forced out at second for a rare 4-6-5 double play.

“He didn’t give in,” Beyeler said of Weiland. “He just kept coming and kept coming and threw some good pitches and kept the ball down for the most part.”

“I was focusing on establishing my off-speed early in the ball game. I did not have that in my last start,” said Weiland, who threw 75 pitches. “It was just  one of those nights where fortunately both of the off-speeds were there from the get-go and it allowed me to be a little more efficient and effective.”

Jeremy Bleich worked around four walks to no-hit the Sea Dogs through 4 2/3 innings. Iglesias finally broke through with a double off the Maine Monster in left, then cut the deficit in half scoring on a Jason Place infield hit behind the second base bag. The Dogs tied it up in the sixth with two out on a double by Anderson and an RBI single by Yamaico Navarro.

Portland’s Andrew Dobies (2 IP, 3 Ks) and Bryce Cox (3 IP, zero hits, 3 Ks) and Trenton’s Wilkin De La Rosa (3 IP, 0 H, 2 Ks) kept the bats silent in relief to send the game to extra innings. Portland loaded the bases against Eric Wordekemper, who intentionally walked Nate Spears to pitch to clean-up hitter Luis Exposito. The Portland catcher struck out swinging then broke his bat slamming it to the ground in frustration.

Brandon Laird (two hits) started the winning rally for the Thunder in the next frame with a one-out single immediately preceding Sublett.

Wordekemper pitched a 1-2-3 bottom of the 11th to end the game.