NEW BRITAIN, Conn. – The Portland Sea Dogs have proven they’re nothing if not relentless.

The Sea Dogs and right-hander Stolmy Pimentel spotted the New Britain Rock Cats an eight-run lead but the offense responded assertively Wednesday night. Portland broke a 10-game road slide with an 18-9 victory in an Eastern League slugfest at New Britain Stadium.

Portland (15-36) scored six runs in the fifth inning, one in the sixth, four in the eighth and six in the ninth in posting the most runs by an Eastern League team this season. New Britain’s winning streak against Portland was snapped at seven.

“We know that we’ve got guys with character, guys that fight,” Portland Manager Kevin Boles said. “They came in the dugout, they were all pumped up, nobody let the score get to them, they took their at-bats, grinded them out, and obviously we’re very happy with the results.”

Jorge Padron drove in five runs, three on his second homer of the season, off a Rock Cats position player in the ninth. Tim Federowicz and Ryan Lavarnway had four hits each to pace a 21-hit offense. Every Portland starter had at least one hit and each had at least one RBI except Alex Hassan, who entered the game as the league’s second-leading hitter. Seven Sea Dogs had multiple hits.

Lavarnway ripped his 12th homer of the season in the ninth and collected three RBI. Will Middlebrooks had two hits, two walks and was hit by a pitch in six plate appearances.

The game featured 34 hits. The Rock Cats, their bullpen decimated by Tuesday’s doubleheader, used shortstop Chris Cates on the mound to mop up. The game lasted 3 hours, 41 minutes.

Cesar Cabral (1-3) tossed three innings of one-hit ball. Kyle Fernandes, who entered the game with the score 12-9, got his first save with two scoreless innings.

But the status of Pimentel as a Red Sox prospect continues to veer toward oblivion.

Pimentel, projected as the fourth-best pitching prospect in the Red Sox system by Baseball America, has had some stormy outings but none stormier than Wednesday night’s debacle. His ERA ballooned to 8.62 after yielding eight earned runs in 11/3 innings.

“The timing is off a little bit. He’s leaving some pitches up in the zone,” Boles said. “We love his ability. We love his fastball, obviously the change-up and the breaking ball. He’s 21 years old and he’s got a major league frame on him with major league stuff. This is part of (the learning process). It isn’t always smooth sailing. This is going to toughen him up.”

Rock Cats starter Deolis Guerra limped through the first four, allowing one run and stranding five, but the Sea Dogs batted around in the fifth. Hassan, Chih-Hsien Chiang, Padron and Vladimir Frias all had doubles to key a six-run rally that brought the Sea Dogs within 9-7.

New Britain reliever Santos Arias walked the first two batters in the sixth and Middlebrooks drilled a two-out RBI single to leave the Sea Dogs just a run short. They made up the difference in the eighth against Bruce Pugh (0-1) on run-scoring hits by Chiang, Federowicz and Jeremy Hazelbaker.