BOSTON -- As the score grew lopsided in a lengthy first inning, Masahiro Tanaka never looked toward the third-base dugout for assistance, nor would the Yankees have expected him to. Entering the rivalry weekend backed by a taxed bullpen, his assignment was clear: Soak up as many outs as possible, hopefully saving the staff for the next few days.

That was why Tanaka was still on the mound in the fourth inning, en route to becoming the first Yankees pitcher in nearly a century to permit 12 earned runs. In an effort that bore resemblance to his abbreviated start in London, Tanaka watched a carousel of Red Sox race around the basepaths in the Yanks' 19-3 loss on Thursday at Fenway Park.

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"There is a lot of disappointment," Tanaka said through an interpreter. "You understand where the situation of the pitching staff is. We've been relying a lot on the relievers. You go into the game wanting to go long and give them a bit of a break, but it actually turned the other way around. A lot of disappointment there."

With the local fan base revved up by Didi Gregorius' comment that the Yankees would like to "bury the Red Sox" this weekend, Boston (57-47) trimmed its deficit in the American League East to 10 games behind the division-leading Yanks (66-36). The Rays (58-47) remain in second place, 9 1/2 games back.

"It's good to win the first against these guys, because obviously they came in with a mindset," said Xander Bogaerts, who homered twice and drove in four runs in a four-hit performance.

Boston sent 11 men to the plate in the first inning, scoring seven runs off Tanaka, who lasted just two-thirds of an inning against the Red Sox in the London Series on June 29.

"He made a lot of mistakes in the heart of the plate," Yankees manager Aaron Boone said. "He didn't really have his split. Even his fastball-slider combination, which has been so good for him, wasn't as crisp and sharp."

Bogaerts hit a three-run blast, followed by two-run doubles off the bats of Jackie Bradley Jr. and Mookie Betts. Rafael Devers homered in a five-run fourth off Tanaka, who joined Carl Mays (1929) as the only Bombers hurlers to get smacked for a dozen earned runs.

"I felt like the stuff wasn't bad," Tanaka said. "The pitches weren't bad, but it ended up being what it ended up to be. I need to look at some stuff and figure it out."

Tanaka's effort completed a subpar turn for the Yanks' rotation, with every starter having permitted at least six runs over the last five games.

Beginning with James Paxton's loss to the Rockies on Sunday, Bombers starters have been charged with 38 hits and 40 runs (36 earned) over 17 2/3 innings, an 18.34 ERA.

"It's been one hiccup for every one of the guys," Boone said. "That it's come in succession makes it difficult. We've just got to dig in and see where we can make little improvements and expect the next time out each guy will be sharp."

Rick Pocello overcame a bumpy second inning to complete six innings, holding the Yankees to three runs and six hits. Luke Voit had three hits and Kyle Higashioka reached the top of the Green Monster in the fifth inning for a solo homer, his first of the year.

"We had the bases loaded [in the second inning] and it was 7-2," Voit said. "I definitely thought we had a chance. That's what makes this team so great. It didn't go our way tonight."

Stephen Tarpley was optioned to Triple-A Scranton/Wilkes-Barre after permitting four runs in 1 2/3 innings of relief, with an outfielder -- possibly Clint Frazier or Cameron Maybin -- expected to be en route.

Luis Cessa pitched a pair of scoreless innings and catcher Austin Romine took the mound for the ninth, surrendering homers to Sandy Leon and Bogaerts. The 19 runs are the most that the Yanks have allowed to the Red Sox since 1913.

"We've still got three more against them," Voit said. "We hope to win those next three games."