BOSTON — Austin Romine was better than Masahiro Tanaka on the mound Thursday night against the Red Sox.

Do you need any more information about how the first of four games between the blood rivals turned out?

Thanks to a rotation that is in a free fall, the Yankees have leaned on a very talented bullpen and a powerful lineup to win games lately.

So when the Red Sox ripped Tanaka for seven runs in the first inning on the way to a 19-3 beating in front of 37,591 at Fenway Park, it was easy to envision a position player taking the ball late in the game.

Seven runs in the first, five in the fourth, three in the fifth, one in the sixth and three against Romine in the eighth was the Red Sox flow chart.

Romine, who pitched in last year’s third game of the ALDS against the Red Sox, followed Stephen Tarpley who was optioned to Triple-A Scranton/Wilkes-Barre after the game.

Romine gave up three runs in his inning, which was four fewer than Tanaka surrendered in the opening frame.

After outslugging the Twins, 24-19, in winning two straight heading into the Red Sox series, the Yankees had one chance to make Boston’s seven-run first not sting, but they failed.

Trailing 7-0 in the second, Gleyber Torres delivered an RBI double and Rick Porcello walked DJ LeMahieu with the bases loaded. Aaron Judge went to the plate with a chance to make it a one-run game, but he flied to the warning track to strand three. It also was the end of the competitive portion of the game.

The victory moved the Red Sox to 10 games back in the AL East, and the 19 runs were the most ever scored by Boston against the Yankees.

While fatigue might have played a part in the embarrassing loss because the Yankees arrived at their hotel after 5 a.m. Thursday, Tanaka flew here ahead of the club yet was pounded for 12 hits and 12 runs in 3¹/₃ innings and seemed dazed when asked why.

“I don’t know at this point,’’ said Tanaka (7-6), who gave up career highs in hits and runs in a second straight bruising by the Red Sox who crushed him for six runs and four hits in two-thirds of an inning in London last month. “I feel like the pitches weren’t bad. I need to look at ­stuff and figure things out.’’

After the second inning, the only noise the Yankees made was Kyle Higashioka’s leadoff homer in the fifth against Porcello, who improved to 9-7 with his fourth straight win since the Yankees pounded him in the same London game the Red Sox rocked Tanaka.

“We got our ass kicked tonight but we had a tough road trip. We got in at 5:30. Not to make excuses, it was just not our night, but we still have three more against them,’’ said Luke Voit, who had three of the Yankees’ seven hits.

Romine didn’t talk about his second big-league mound appearance and Tanaka couldn’t offer why he was hit so hard.

“I am not sure at this time why I wasn’t able to get outs,’’ said Tanaka, who has a 4.79 ERA and looks nothing like a pitcher capable of starting Game 1 of a postseason series.

What Tanaka did say was that he let the Yankees down.

“Lot of disappointment,’’ he answered when asked what his thoughts were about a pitching line that would make any pitcher at any level cringe. “We have been relying a lot on the relievers. You go into the game wanting to go long and give them a bit of a break and it actually turned the other way around so there is a lot of disappointment.’’