Luis Severino brought his usual toolbox to the mound Sunday night.

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It included the fastball that routinely hits 97 mph and a darting slider, two pitches that for several years have had the Yankees dreaming of a future ace.

But there also were the mistakes. There weren’t as many as in his five previous starts this season, but there were enough to beat him and the Yankees.

Though he struck out a season-high nine in 6 2⁄3 innings, the winless Severino allowed three home runs in a 5-1 loss to the Red Sox, who received a brilliant three-hitter from knuckleballer Steven Wright in front of 41,869 at the Stadium.

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“I’m going to get through this,” said Severino, who fell to 0-5 with a 6.12 ERA.

Wright (3-3, 1.52) became the first Boston pitcher with a nine-inning complete-game win against the Yankees since Jon Lester on July 3, 2008.

Severino, 22, allowed four runs and five hits, two of them homers by David Ortiz.

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Dustin Pedroia’s two-run blast in the first inning, an opposite-field shot that just eluded a leaping attempt by rightfielder Carlos Beltran, created a 2-0 deficit for the Yankees (11-18).

Ortiz added solo shots in the fourth and seventh innings, both on poorly placed fastballs from Severino.

Xander Bogaerts’ solo shot in the eighth off Chasen Shreve, who has allowed four homers in his last 5 2⁄3 innings, made it 5-0.

Brett Gardner’s two-out homer in the ninth inning spoiled Wright’s shutout.

Starlin Castro left the game with what was characterized as a minor rib-cage injury.

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Loss aside, there were encouraging signs from Severino. He walked one and at one point struck out seven of nine batters, in large part because of an arsenal of secondary pitches — specifically his slider and changeup — that were as sharp as they’ve been this season.

“I actually think the kid is really close,” Joe Girardi said of Severino resembling the pitcher he was late last season, when he went 5-3, 2.89 in 11 starts after being called up from the minors. “If he’s throwing the ball like tonight, he’s going to win games if we score runs.”

Which they frequently don’t do. In their 29 games, the Yankees have scored three or fewer runs 21 times (4-17) and two or fewer runs 15 times (0-15).

Though the 40-year-old Ortiz, slated to retire after the season, continued in his role as the top Yankee-killer of this generation, the star for the Red Sox (18-13) was Wright.

The 31-year-old righthander was masterful as the teams sailed to the finish line in 2 hours, 27 minutes. He walked one and struck out seven.

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“He had total control of it tonight,” Brian McCann said of Wright’s knuckleball. “I felt like he could do whatever he wanted with the ball tonight.”

The Yankees managed one hit in the first six innings as Wright needed only 60 pitches to navigate the stretch. They didn’t get a runner in scoring position until Castro led off the seventh with a double. He tagged and went to third on McCann’s fly to right but was picked off during Mark Teixeira’s ensuing at-bat.

Girardi said he “felt something in the back of his [left] rib cage” while diving back to third. Castro stayed in but Girardi pinch hit for him in the bottom of the ninth with Ronald Torreyes.

“I said I could still play but he [Girardi] said he didn’t want to take a chance,” Castro said. “Hopefully tomorrow I’ll be all right.”