PORTLAND — The Portland Sea Dogs struggled on the mound Monday night in the first game of a doubleheader.

Both starter Chris Martin and reliever Caleb Clay gave up six runs (five earned) as the Trenton Thunder topped the Sea Dogs 12-4, before 5,557 at Hadlock Field.

The Thunder then completed the sweep with a 5-3 win in the second game.

In the first game, Drew Hedman hit a three-run homer for the Sea Dogs

Martin (3-5) did not get out of the first inning, allowing seven hits and two walks.

“He left a few pitches up in the zone,” Sea Dogs Manager Kevin Boles said. “It didn’t look like his stuff was very crisp tonight as far as his off speed goes.

“Threw some quality fastballs, but it didn’t look like he was able to utilize a mix (of pitches).”

In Martin’s previous three appearances, he gave up a total of two earned runs.

Clay had also been pitching well (two earned runs in his last eight innings), and he began Monday’s effort by retiring four straight batters.

But Trenton began the fifth by going home run (Zoilo Almonte), single and home run (Luke Murton).

The highlight of the Sea Dogs’ pitching efforts was turned in by Josh Fields, who relieved Clay in the seventh and retired the final three batters on 17 pitches (12 strikes).

Fields has not allowed an earned run in his last five appearances (nine innings), giving up one hit and three walks, striking out 11.

“He’s had better zone command,” Boles said, “and his breaking ball is coming around. That thing is starting to get sharper and sharper, and he’s throwing it early in the count for strikes.”

Fields, 26, was a first-round draft pick of the Seattle Mariners in 2008, out of the University of Georgia. He came to the Red Sox organization last year, along with major league left-hander Erik Bedard, in the multi-player deal that sent outfielder Chih-Hsien Chiang to the Mariners, and catcher Tim Federowicz and pitcher Stephen Fife to the Dodgers.

Fields had a 3.12 ERA in nine appearances last year for Portland. He’s been up and down this year, but is on a nice roll. “Looks like his delivery is in sync,” Boles said.

“His fastball command is coming along. Looks like he’s settling in.”

Portland’s offense showed life in the fourth inning when Matt Spring doubled to left and Peter Hissey followed with a single to right. After an out, Hedman crushed an 0-1 fastball over the right field wall, closing the Sea Dogs to 6-3.

The only other Sea Dogs run came in the sixth. Ryan Dent and Jackie Bradley Jr. both singled. Dent reached third on a ground-out and scored on a balk.

In the second game, Trenton broke a 3-3 tie with three hits and two runs in the seventh off spot starter Jeremy Kehrt (2-3). Zach Gentile, Hissey and Bradley had RBI for Portland.

NOTES: Dustin Pedroia fans had their dedication tested late Monday afternoon. Hundreds lined up at Hadlock Field to get a free Pedroia bobblehead doll. But just before the gates opened, the skies opened and a downpour soaked the fans.

Staff Writer Kevin Thomas can be contacted at 791-6411 or at: kthomas@pressherald.com

Twitter: ClearTheBases