Masahiro Tanaka helps Yankees earn fourth straight victory

OAKLAND, Calif. — Suddenly, the Yankees’ rotation is performing as the club expected.

Unsurprisingly, a string of victories has followed.

Masahiro Tanaka was the latest starter to produce, shaking off consecutive poor outings in a 5-1 victory over the A’s on Saturday afternoon in front of 26,356 at O.co Coliseum.

Tanaka became the fourth consecutive Yankees starter to allow one run. In those four games, Nathan Eovaldi, Ivan Nova, CC Sabathia and Tanaka have given up 13 hits and three walks in 25 innings, striking out 20. They have a 1.44 ERA in the four games.

“They feed off of each other,” Chase Headley said of the pitching and the offense, which also has come alive. “But obviously the game’s built around starting pitching, and when they go out and throw the ball like that, we’re going to win a lot of games.”

The Yankees (20-22) extended their winning streak to a season-high four games (and 11 of 16) and will go for a four-game sweep this afternoon against the A’s (19-25), who entered the series with four straight victories but have played poorly in the first three games.

The victory also allowed the Yankees to emerge from the AL East cellar. “That’s better than being in last place,” Joe Girardi said. “You keep trying to climb.”

His club can complete a 5-2 trip, which started with two losses in Phoenix, if struggling righty Michael Pineda can become the fifth starter in a row to pitch well. “I think they want to outdo what the guy did the night before,” Girardi said. “So it’s Michael’s turn [Sunday].’’

Tanaka (2-0, 3.24), who allowed 10 runs in 12 innings in his previous two outings while pitching on four days’ rest each time, gave up one run and five hits in seven innings on five days’ rest. The Yankees tweaked his schedule last season to give him more games on five days’ rest, and Girardi said they’ll continue to do that this season when they can.

“Sometimes you feel a little bit more rested,” Tanaka said through his translator. “But I’m always preparing myself to go on the fifth day. That’s really not a problem for me.”

He got into bases-loaded, one-out jams in the third and fifth but allowed only one run to score.

The four-run lead allowed Girardi to rest Dellin Betances, Andrew Miller and Aroldis Chapman for a second straight game.

The Yankees, who had eight hits, did most of their damage against A’s lefthander Sean Manaea in a four-run fourth that snapped a scoreless tie.

Manaea (1-2, 7.62), who allowed five runs and six hits in 6 2⁄3 innings, held the Yankees without a hit for the first three innings. Then Jacoby Ellsbury walked, Starlin Castro reached on an infield single and Mark Teixeira, 10-for-62 to that point this month, walked to load the bases with none out in the fourth.

Carlos Beltran, who had three RBIs in each of the previous two games, lined an RBI single off the glove of shortstop Marcus Semien and Aaron Hicks’ sacrifice fly to left made it 2-0.

With two outs, Rob Refsnyder — making his first big-league start of the season — fought off three full-count pitches before hitting a two-run double that one-hopped the wall in right-center to make it 4-0. That capped a 10-pitch at-bat.

Ronald Torreyes singled and scored on Castro’s two-out double in the seventh to make it 5-1.

“We had a really good home stand where we won seven out of 10 against three good teams [the Red Sox, Royals and White Sox], but at the same token, we hadn’t gotten on a streak like this,” said Headley, who had a hit to make it 12 straight games in which he’s reached base. “So it’s important to get on those, and hopefully we can keep it going.”