PORTLAND — The pitching matchup between the Portland Sea Dogs and Trenton Thunder on Monday went just as predicted.

Or maybe it didn’t.

Actually, the battle of the starting pitchers finished somewhere in the middle, and was made moot when the game went to extra innings. The Sea Dogs walked off with an 8-7 victory in 10 innings at Hadlock Field to salvage the final game of the four-game series.

Deiner Lopez dropped the game-winning single under the glove of diving Trenton left fielder Mark Payton to score Cole Sturgeon.

Sea Dogs starter Travis Lakins entered the game as a top prospect for the Boston Red Sox (No. 7 in the farm system, according to MLB Pipeline), but struggled in his first two starts for Portland after getting called up from High-A Salem.

Opposing Lakins was Trenton starter Ronald Herrera, who wasn’t among the New York Yankees’ top 30 prospects according to MLB Pipeline, but who entered Monday’s contest 5-0 with a 1.47 ERA in five Double-A starts.

Through five innings, it looked like the prospect ranking was overruling the production. Lakins had allowed just one run on one hit, and the Sea Dogs led 3-1. Portland scored those three runs on six hits against Herrera, who was also done in by two costly errors through five innings.

“This time I kept the ball down in the zone,” Lakins said. “Everything was more down in the zone, and it worked out for me today.”

Then Lakins, who pitched a combined six innings in his first two Double-A starts, came on for the sixth inning against the Eastern League-leading Thunder. He walked Trenton leadoff batter Thairo Estrada on a 3-2 pitch to start the frame, then threw wide of second on a Mark Payton fielder’s choice grounder for an error.

“I thought I should have made a good throw on the double play. I tried to get it out as quick as possible and kind of rushed it, and led (Lopez) off the bag,” Lakins said. “But I thought my outing was pretty good today, and I liked everything how it worked out.”

That was it for Lakins, who threw 93 pitches (54 strikes) in five-plus innings.

“Better today. I thought he was much better,” Sea Dogs manager Carlos Febles said. “He made pitches when he needed to. That was nice to see that from him. He competed, and unfortunately that sixth inning, that walk and a chance to double play kind of kicked him in the butt. Other than that I was happy with his outing.”

On came reliever Jacob Dahlstrand, who lost his spot in the Sea Dogs’ rotation when Lakins was called up. Dahlstrand walked the first three batters he faced, scoring two runs that were charged to Lakins. A double-play grounder and a fielding error scored two more runs, charged to Dahlstrand, to put the Thunder up 5-3.

Herrera had arguably his worst start of the season, but he left the game with a 5-4 lead after six innings. He allowed season-highs with six hits and four runs, though three of those were his first three unearned runs given up this season.

The Sea Dogs got the scoring going in the bottom of the first. Danny Mars led off with an infield single and moved to second on a throwing error. Two batters later, Rafael Devers — the No. 1 prospect in the Red Sox system — smacked a double just short of the wall in right to drive in Mars.

Trenton answered in the top half of the second. Lakins walked the first two batters, both on 3-2 pitches, before a Rashad Crawford sacrifice bunt and Billy Fleming single scored Mike Ford.

Portland had a chance to re-take the lead in the fourth after Nick Longhi and Jeremy Barfield hit consecutive singles to start the frame, and a Sturgeon sac bunt moved them both into scoring position. But Longhi was gunned down at home by Billy McKinney trying to score on a fly out to right.

The Sea Dogs did get the lead back in the fifth. Jordan Procyshen walked to lead off, then moved to third on Lopez’s single. A Mars RBI groundout scored one run, and a fielding error by Herrera — who took a throw from first baseman Ford to the face while trying to cover first — brought home another, making it 3-1.

The Thunder stretched their lead to 6-4 in the seventh on a leadoff single by Abiatal Avelino and a two-out double from Miguel Andujar. A Barfield solo home run — his first with the Sea Dogs — cut the lead to one in the eighth, then an Estrada solo shot made it 7-5 in the top of the ninth.

Portland was able to rally the game back to even in the bottom of the ninth against Trenton reliever Colten Brewer. Joseph Monge led off with a single, then Procyshen followed by walking on a 3-2 pitch. Lopez moved both runners into scoring position with a sac bunt before Mars drove both runs in with a ground-rule double down the third-base line. Mars was left stranded there, however, sending the game to extra innings.

“This is a team that, once they have the lead late, it seems like they’re tough to beat,” Febles said. “They have some pitching, and we were able to put some pretty good at-bats together to score runs late and get the ball game.”

After Yankory Pimentel worked around a one-out walk in the top of the 10th, Sturgeon reached with one out in the bottom half thanks to a broken-bat, infield single. Monge followed with a single to center, and Procyshen moved them both over with a groundout to first.

“When you’re struggling to score runs like we have been, you kind of got to put together at-bats and just do the little things, and they add up,” Sturgeon said. “And that’s what happened today.”

Lopez then sent the first pitch he saw from Brewer to left, where Payton’s diving attempt came up just short.

“There’s two outs, so you’re going no matter what. Luckily it fell. (Brewer) is tough, and (Lopez) had a good swing,” Sturgeon said. “It felt good. Especially winning the last game (of the series), getting on the road, feeling good about going on the road.”

The Sea Dogs now head out on the road to Reading, which sits just above Portland in the Eastern Division standings.

wkramlich@sunjournal.com