BOSTON — After two straight meltdowns by the Red Sox’ bullpen to open this series, the Seattle Mariners had an epic collapse of their own Sunday.

 The Mariners’ bullpen caved in an ugly seventh inning that saw the Red Sox rally for five runs and win going away, 8-4. The Sox are now 49-32 at the halfway point of the season, the exact same record they enjoyed in 2008.

 If the team is going to maintain its slim lead over the Yankees and the Rays through the second half, a consistent bullpen is a must. After rocky outings from Ramon Ramirez and Takashi Saito in the first two games of this series, the Sox’ pen reverted to form in Sunday’s game as Justin Masterson and Hideki Okajima retired all seven Mariners they faced to nail down the win.

 The victory helped the Sox avert their first series sweep of the season, a fact not lost on a prideful group of players.

 “They came in and took two in very close games, but it’s the character of our team,” said Jason Bay, one of six Red Sox named to the All-Star Game. “It doesn’t matter if we’re getting no-hit, one-hit — we’ll put up four in the eighth. We always know we have the personnel to do that.”

 The Sox found themselves in a bind in the final game of this series as well. Two mental errors cost the Sox in a three-run fourth inning that helped the Mariners to a 4-2 lead through five innings. But the Sox kept chipping away. Jacoby Ellsbury hit a solo home run off Seattle starter Brandon Morrow in the sixth inning and when the Mariners went to their bullpen in the seventh, the Sox were ready to pounce.

 After one out, reliever Miguel Batista walked J.D. Drew, and Dustin Pedroia rocked his third hit of the game — a single to left — to put runners on the corners. David Ortiz then lined a 3-and-0 fastball to right for a single that pushed across the tying run.

 “I always got the green light,” Ortiz said. “Sometimes they give you a strike, but it’s not a pitch to drive.”

 Asked if he felt Batista’s offering was drivable, Ortiz smiled and answered, 'What do you think?”

 That was it for Batista but his replacement, Mark Lowe, was even worse. He walked Bay on four pitches to load the bases. Ellsbury then walked on five pitches to force in Pedroia with the go-ahead run and give the Red Sox a 5-4 lead. Next up was Mark Kotsay. Lowe continued to struggle (only two strikes in his first 13 pitches) and fell behind in the count again. Kotsay made him pay with a line-drive single to right that scored two more runs.

 Sean White came in for Lowe to face Jason Varitek and before he struck out the Sox’ catcher, one pitch flicked off catcher Kenji Johjima’s glove for a passed ball that allowed Ellsbury to score easily and Boston led, 8-4.

 “The leadoff walk (to Drew) kind of started the momentum for Boston,” said Seattle manager Don Wakamatsu. “In this ballpark it’s tough to get it back sometimes. I think the command for (Batista and Lowe) just kind of left for the day.”

 The big inning was just what the Red Sox needed to break out of a mini offensive funk.

 “When you see a guy has command issues, you always want to get deeper in the count,” said Kotsay. “When they get behind, they’re not as concerned with locating (pitches) as just throwing it over the plate so you can see a better pitch to hit.”

 Boston’s bullpen came up big in relief of Jon Lester. The lefty allowed four runs but three were unearned thanks to a error by Pedroia in the fourth inning. The four runs were the most given up by Lester in his last seven starts. He’s surrendered one or fewer earned runs in five of his last seven starts.

 Masterson dominated the four Mariners he faced, striking out three and bridging the gap between Lester and Hideki Okajima. The Japanese lefty then set the Mariners down in order in the ninth.

 “I don’t think many people appreciate what the bullpen needs to do and that’s because perfection is expected,” said Masterson. “We expect it, too, but it just doesn’t happen.”

 Masterson pointed out that a two-run outing over six innings by a starter is very good. A two-run inning by a reliever is a disaster. Those disasters spelled doom for the Sox twice this weekend and ultimately did in the Mariners on Sunday.