Masahiro Tanaka has yet to resemble the pitcher he was last season when he contended for the American League ERA title.

But he’s closing in fast.

His fourth start of the campaign was by far his best and, backed by homers from Chase Headley, Starlin Castro, Aaron Judge and Aaron Hicks, Tanaka and the Yankees cruised to a 9-1 victory over the White Sox on Wednesday night on a crisp, 46-degree night at the Stadium.

The Yankees (10-5), who went 8-1 on their nine-game home stand, start a six-game trip Friday in Pittsburgh, followed by three games in Boston.

“It shows this is a really good baseball team,” Austin Romine said. “I think people are seeing that now.”

Tanaka (2-1), who lugged an 8.36 ERA into the night, allowed one run, six hits and two walks in a season-best seven innings. The righthander, with as good a split as he’s had early this season, struck out six. Though there were some command issues, Tanaka avoided the big mistake.

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“I think I’m definitely making a stride toward the right direction,” Tanaka said through his translator. “It’s getting better, obviously, but it could be much better, so I’ll make adjustments until my next start and go from there.”

The Yankees’ offense entered fourth in the AL in runs (68) and took the league lead in homers (22) on Wednesday night when they overmatched righthander Dylan Covey (0-1), making just his second career start. The 25-year-old allowed eight runs and 10 hits over five innings.

Castro’s three-run homer in the fifth, followed by another long home run by Judge, opened up a somewhat close game, the back-to-back blasts making it 8-1. Judge’s blast landed in the upper rows of bleachers in left-center, a seldom-reached area of the Stadium, and was estimated to have traveled 448 feet, 11 feet shy of the shot hit Monday night by Matt Holliday.

“I thought I had him tonight,” Judge said with a smile.

Joe Girardi called Judge’s shot “maybe the furthest I’ve seen here to left-center.”

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“I’d question the distance they measured that at,” Girardi said. “But he’s swinging the bat great.”

Judge, who struck out 42 times in 84 at-bats last year after getting called up, is hitting .277/.358/.660, with a club-best five homers.

Castro even credited the 6-7, 280-pound Judge for his home run, which came on a 3-and-0 pitch.

“With Judge behind me, he [Covey] doesn’t want to walk me,” Castro said, adding of Judge’s shot, “I’ve never seen a home run like that.”

Hicks, pinch hitting in the eighth, homered off righty Michael Ynoa to make it 9-1.

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Headley’s two-run homer in the first, his third of the season, got the Yankees on the board.

Tanaka’s performance, meanwhile, was the continuation of a trend of standout starting pitching on the homestand. Yankees starters have recorded seven straight quality starts and have a combined 2.69 ERA over their last 10 starts. What most agreed to be the club’s biggest question entering the season to this point has been a strength.

“It’s been really nice to come home and play extremely well,” Girardi said. “It was important. I think I was probably most impressed by our pitching. Our pitching was really good, and to be successful in this league, it starts with your starting pitching. When they give you a chance to win every night you have a chance to run off streaks like this.”