Miguel Andujar’s seventh-inning grand slam put a charge into Yankee Stadium on Saturday, as the team tried to snap out of its second-half doldrums by overcoming a seven-run deficit.

Instead, a late rally ended right there, and the Yankees lost for the third time in four games in an 8-7 defeat to the Blue Jays.

They managed to keep their 1½-game lead for the top spot in the AL wild-card race only because Oakland lost to Tampa Bay, but the Yankees still dropped another game to a bad team, as they continue to stagger to the finish line of the regular season.

“We’re in a dogfight,’’ Aaron Boone said. “What [the A’s] do doesn’t change it. These games are really important and it’s important we put our best foot forward. We’re in a good position to get to where we want to go, but we’ve got to go take it.”

In a six-run seventh, it seemed like the Yankees might just do that.

Trailing 8-1 to start the inning, they got solo homers from Giancarlo Stanton and Didi Gregorius.

Gleyber Torres doubled with two out, and Neil Walker and Luke Voit followed with walks to load the bases for Andujar, whose grand slam off ex-Yankee Tyler Clippard brought the Yankees to within a run.

But Andrew McCutchen struck out to end the inning and in the eighth, with Aaron Hicks on second and two out, Ken Giles whiffed Gary Sanchez to finish the inning and the Yankees didn’t threaten again.

“That was a frustrating one there,’’ Boone said.

“We’re not doing what we’re supposed to do with runners in scoring position,’’ Gregorius said of the Yankees, who were 1-for-7 with runners in scoring position until Andujar’s blast. “We’re not scoring runs. That’s the main thing.”

But it isn’t the only thing.

They also got another clunker from CC Sabathia, who gave up five runs in just 2 ¹/₃ innings, his shortest outing of the season.

He allowed three homers before Chad Green and Jonathan Holder took over and provided 3 ²/₃ scoreless innings.

Boone then opted to go with Tommy Kahnle over David Robertson with the Yankees down 5-1.

“Had we got [the deficit down] to two or three runs, we would have [gone to Robertson],’’ Boone said. “If you’re four or five runs down and you use up all your [high]-leverage guys, you’ve got to be prudent at some point.’’

The move backfired.

Kahnle loaded the bases before getting the next two batters out, but Aledymas Diaz blooped a single into center for two more runs before Stephen Tarpley allowed a run-scoring single to Richard Urena.

The Yankees stormed back against the Blue Jays’ dreadful bullpen after they were blanked for five innings by Sean Reid- Foley, who they pounded for eight runs in 4 ¹/₃ innings last month in The Bronx.

But much has changed since August.

Since completing a four-game sweep in Baltimore on Aug. 26, the Yankees have gone 8-10 while playing also-rans like the White Sox, Tigers and Twins — in addition to Toronto.

Boone remained optimistic after the latest setback. Asked when he would worry about how his team was playing, the rookie manager said, “When we go home.”

“We have a group in there capable of turning this thing in a heartbeat,’’ Boone said. “We’ve just got to keep battling through this right now. We’re showing some signs of pulling ourselves out of it a little bit, [but] we’ve got to do better. We’ve got to be more consistent.”

Gregorius echoed Boone’s sentiments.

“We’re supposed to win,’’ the shortstop said. “We’re not playing that way right now, but we’ll pick it up soon.”