SEATTLE -- David Ortiz was starting to get more than a little frustrated.
In the sixth inning, he snapped his bat over his knee after popping up to third base. His next time up, he made the ball pay instead.
"I've been missing a lot of pitches lately and I don't know why," Ortiz said. "I got frustrated by it. I'm not a guy that's used to missing pitches because I don't get that many pitches to hit.
"You either get on top or under the ball a half an inch different. Drives me nuts."
Jed Lowrie homered twice for Boston, which is seven games behind New York and third in the American League East.
Despite having only one home run in April, Ortiz now has gone for more than 30 for the sixth time in his career, matching Manny Ramirez for second most in franchise history behind Ted Williams' eight seasons of 30-plus.
"I'm not even close to what Mr. Williams was," Ortiz said. "What he meant for this organization, he played for so many years and with so many great names. For my name to be right next to him is a huge compliment for me."
League (9-7) entered the game in relief of starter Luke French and quickly retired his first two batters. Victor Martinez and Adrian Beltre followed with a pair of singles, and League served up a fastball on the inner half of the plate that Ortiz drilled over the wall in right-center field to give the Red Sox a 7-5 lead.
"It was the perfect example of what happens when your sinkerball doesn't sink," League said.
Mariners manager Daren Brown had lefty Garrett Olson available in the bullpen to face Ortiz, who is batting just .208 with two home runs against left-handers, but decided to stick with League.
"League's got good stuff. I'd trust him against anybody," Brown said. "In the same situation tomorrow. League's got good stuff; I'd have no doubt he'd get the job done."
After League walked Varitek to lead off the ninth, Eric Patterson stole second as a pinch runner, moved to third on a groundout by Daniel Nava and scored on a fielder's choice by Ryan Kalish. Josh Reddick followed with an RBI single to make it 9-5.
"They take the lead and David, with one real good swing, changes the whole complexion of the game," Red Sox manager Terry Francona said.
The Mariners added a run in the ninth inning. Rich Hill (1-0) made his first appearance since July 27, 2009, with Baltimore.
Lowrie hit his first of two home runs off Mariners starter Luke French in the second inning with a runner on to put the Red Sox on top.
Lowrie struck again in the fourth with a solo shot over a leaping Michael Saunders to take a 4-2 lead. French managed to settle down and retire his final 12 batters.
Daisuke Matsuzaka drilled Josh Wilson to lead off the fifth inning and Seattle capitalized on the mistake. Ichiro Suzuki doubled to left-center field to score Wilson from first. After Chone Figgins reached on a bunt, Branyan hit a sacrifice fly to right field to score Suzuki and tie the game at 4.
"There's times, there's innings he makes it tough on himself," Francona said of Matsuzaka. "He looks healthy. Ball is coming out of hand good. Just he wasn't terribly consistent tonight."
A leadoff single from Suzuki chased Matsuzaka in the seventh inning. Figgins sacrificed Suzuki to second base and Gutierrez drove him in with a two-out double off the wall in left-center field to give the Mariners the lead.
Red Sox C Jason Varitek got his first start since June 30 against Tampa Bay. Varitek missed two months with a fracture in his right foot. He was 0-for-3 with a walk. ... The Mariners ran on Varitek six times, stealing four bases. ... 3B Adrian Beltre set a Red Sox record with his 71st extra-base hit of the season, a double in the second inning, moving out of a tie with Wade Boggs. The double also moved him into the lead for most extra-base hits in the majors this season, surpassing Evan Longoria of Tampa Bay. ... Figgins' four hits were a season high.