NEW BRITAIN, Conn. – Successful repetition in the late innings is breeding confidence for the Portland Sea Dogs’ hitters.

Of course, the ineptitude of the New Britain Rock Cats’ bullpen has something to do with it, too.

For the second straight game, the Sea Dogs overcame a late deficit with a six-run inning, humbling the Rock Cats 9-5 before a sold-out crowd of 6,294 at New Britain Stadium.

With one out in the eighth inning and the Sea Dogs (38-36) trailing 5-3, six straight hitters reached base to spoil righthander Billy Bullock’s Double-A debut.

Bullock (0-1) got the first out of the eighth, but Ryan Khoury singled and Chih-Hsien Chiang doubled on an 0-2 pitch. Will Vazquez walked to load the bases, and Matt Sheely tied the game with a two-run double.

Bullock hit Che-Hsuan Lin with a pitch before yielding another two-run double to Nate Spears. Lin and Spears scored when catcher Danny Lehmann could not corral Juan Portes’ throw from third on Ray Chang’s fielder’s choice grounder.

The scene was remarkably similar to Saturday night’s game, when Portland used a six-run seventh to erase a four-run deficit en route to an 8-5 win.

“From a mind-set standpoint, you feel like you’re never out of things, but we try to feel that way every night,” Portland Manager Arnie Beyeler said. “We talk to the guys about not giving at-bats away, playing a hard for nine innings and getting after it. If you don’t respect the game, it comes back and bites you.

“We’ve been somewhat successful against these guys here (8-1 in New Britain), but they’ve kind of helped us out with errors and walks. We’ve been fortunate to take advantage of that stuff.”

The New Britain bullpen has blown 64 percent of its save opportunities (16 of 25) and has a 6.00 ERA.

Reliever Ryne Lawson (4-2) allowed two runs in 21/3 innings but benefited from Portland’s outburst. New Britain took the lead against him in the seventh. A single by Chris Cates and a bunt single by Ben Revere got it started preceded Joe Benson’s triple off the right-field wall.

“You see some excitement,” said Rock Cats Manager Jeff Smith, who played in 10 games for the Sea Dogs in 2003. “You see us coming back, you see us take leads, but unfortunately we’re not finishing nine innings of baseball.”

Portland took a 2-0 lead in the second inning off Cats starter David Bromberg, with the bottom of the order doing most of the damage after two were out. Vazquez was hit by a pitch and Sheely, the No. 9 hitter, singled. Lin slapped an RBI single to right, and Sheely also scored when Chris Parmelee was unable to field the ball cleanly.

The Rock Cats responded in the home half against righthander Alex Wilson.

Jair Fernandez crushed his first Double-A home run with one out and the bases empty. Parmelee rifled a shot up the alley in left-center and scored when Lehmann did the same with two out.

Chiang broke the tie for the Sea Dogs with his fifth homer of the year leading off the fourth, but Portland gave the run back the next inning.

Spears, in just his second game at shortstop, misplayed Lehmann’s grounder for a two-base error. Cates sacrificed Lehmann to third, and Revere lashed a run-scoring single to right to tie the game at 3.

A single by Steve Singleton and an outfield miscue put runners on second and third with one out, but Wilson got the No. 3 and No. 4 hitters — Benson and Erik Lis — on short pop flies.

The Sea Dogs made two errors both Saturday and Sunday, leading to an unearned run in both games.

“Defensively we have to do a better job of not giving extra outs to teams because it comes back and hurts you,” Beyeler said.