SEATTLE -- It took five hours and a pair of two-out runs in the bottom of the 13th inning, but the Mariners pulled out a 6-5 win over the Red Sox on a walk-off single by Jean Segura to hand Boston its season-high fourth straight loss on Tuesday night at Safeco FIeld.
Sandy Leon singled in Hanley Ramirez for the go-ahead run in the top of the 13th, but the Mariners rallied in the bottom of the frame off Doug Fister. A wild pitch by Fister allowed Ben Gamel to score the tying run from third with two outs before Segura pushed a ground ball up the middle to score Guillermo Heredia for the game winner.
"It was an awesome effort by our entire club just to hang in there," said Mariners manager Scott Servais. "This was an important game. We know where we're at and we've talked about trying to win series. I can't say enough about the effort. They just never quit."
The loss dropped the Red Sox to 55-47 and narrowed their lead over the Yankees to one game in the American League East. During the game, Boston finalized a trade with the Giants to acquire Eduardo Nunez for two Minor League pitchers.
"It's a tough loss -- particularly in the stretch of games in which we are in and the way we scuffled offensively for a period of time now," said Red Sox manager John Farrell. "But make no mistake, our guys kept grinding. We used everybody available to us tonight, there was tremendous energy in the dugout throughout."
Seattle pulled back to .500 at 51-51, 2 1/2 games back of the Royals for the second AL Wild Card spot.
Highly touted Red Sox prospect Rafael Devers made his Major League debut and went 0-for-4 with two walks and looked solid at third base.
"For me it's just going out there and playing my brand of baseball and having fun out there," said Devers. "That's what I was trying to do and I think I did that."
Felix Hernandez sailed through five innings with a 3-1 lead, but the Red Sox jumped on him for three runs in the sixth with a two-run double by Dustin Pedroia and an RBI single by Jackie Bradley Jr. Hernandez had allowed just two runs over 18 innings in his previous three outings, but gave up four runs over 5 2/3 frames on four hits and two walks to the Sox as he remained 5-4 with a 4.08 ERA.
Seven Mariners relievers combined to throw seven scoreless innings before Leon's RBI single off Tony Zych in the 13th, but Zych got the win with his two innings of work when Seattle pulled out its sixth walk-off victory of the year.
"Unbelievable win," said Zych. "Any win is great, but when you do it like that and it's a total team effort, it's really exciting."
Boston southpaw Thomas Pomeranz (10-4, 3.59 ERA) surrendered a three-run homer to Guillermo Heredia in the second, but that was the only damage allowed in a five-inning outing that included four hits, four walks and seven strikeouts.
MOMENTS THAT MATTERED
Pedroia delivers big double: Hernandez had thrown only 64 pitches through the first five innings, but the Mariners veteran wobbled in the sixth when he walked rookies Devers and Andrew Benintendi. A wild pitch moved the runners to second and third and set up Pedroia's two-run double to left to tie the game at 3. Hernandez wound up throwing 31 pitches that frame and was taken out after Bradley's go-ahead single with two outs.
Zunino unloads: The Mariners catcher has cooled off after a torrid June when he ripped 10 homers and 33 RBIs, batting just .182 in July (10-for-55). But his second homer in the past three games was a big one as he tied the game back up at 4 with a 413-foot shot off reliever Richard Hembree leading off the seventh. Zunino's fourth homer of the month gave him 15 for the season.
"In my opinion, the biggest play of the game was Heredia going from first to third on the wild pitch, keeping his head up there and taking the extra base, which allowed him to score the winning run there." -- Servais on the play in the 13th inning when Gamel scored the tying run and Heredia moved into position to score on Segura's winning hit
"He handled himself well here tonight. He made some impressive plays here defensively. He was very calm, collected, was a good impression here tonight." -- Farrell on the debut of Devers
SOUND SMART WITH YOUR FRIENDS
The good news for Craig Kimbrel is that he threw the fastest pitch of his career on Tuesday against the Mariners. The bad news? It resulted in a base hit. His 101.2 mph offering down the middle of the plate for Danny Valencia, who hit a line drive opposite field for a base hit. It the second fastest was the fastest pitch that's resulted in a base hit this season, according to Statcast™, just trailing Mookie Betts' hit off a 101.3 mph pitch by Yankees' closer Albertin Chapman.
Nick Vincent threw a scoreless 10th inning for the Mariners and has not allowed a run in 22 2/3 innings over 24 appearances at Safeco Field this season. The 24 scoreless home appearances streak tied George Sherrill (2007) for the club record.
Red Sox: Ace Chris Sale started this road trip for the Red Sox with a gem against the Angels, and he'll try to close the trip in the same fashion when the takes the ball for Wednedsay's 3:40 p.m. ET finale at Safeco Field. Sale notched his 200th strikeout last time out, joining Nolan Ryan, Randy Johnson and Pedro Martinez as the only pitchers in history to strike out that many batters within the first 20 starts of a season.
Mariners:Andrew Moore (1-2, 5.70 ERA) makes his sixth start since moving into the rotation in Wednesday's 12:40 p.m. PT series finale with the Red Sox. The 23-year-old rookie has allowed 10 runs on 15 hits -- including four homers -- in nine innings over his last two starts.
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