ARLINGTON, Texas — The Yankees offense threatened to waste Carlos Rodon’s strong start.

Then, once the bats did their job, the bullpen spoiled it all anyway.

After a DJ LeMahieu fielding error opened the door for a two-run rally against Jake Cousins in the bottom of the eighth that trimmed their lead to one run, Clay Holmes blew it in the bottom of the ninth as the Rangers walked off with a 7-4 win over the Yankees on Tuesday night at Globe Life Field.

Wyatt Langford delivered the final blow, crushing a grand slam to left field.

Holmes, who had walked back-to-back batters to load the bases with one out, threw a slider over the heart of the plate and Langford clobbered it to seal a brutal night for the Yankees.

With the crushing loss — their fifth in the last seven games — the Yankees (80-59) dropped into second place in the AL East for the first time since Aug. 20, with the Orioles moving into first by a half-game.

Rodon had fanned a season-high 11 across six strong innings of one-run ball in which the only hit he allowed was a solo home run to Josh Jung in the fourth inning.

While Rodon has enjoyed mostly strong run support this season — the Yankees’ 5.2 runs per start of his ranked ninth among qualified starters coming into the night — his offense made him sweat it out on Tuesday.

Rangers left-hander Andrew Heaney, briefly a Yankee in 2021, kept them scoreless across five-plus innings in which he allowed just three hits and one walk while striking out eight.

But Jazz Chisholm Jr. and Anthony Volpe got the seventh-inning rally started with singles off Jose Leclerc.

Then, with Jose Trevino at the plate, Chisholm kept extending his lead off second base and eventually took off for third, which distracted Leclerc and stopped him mid-delivery, allowing Chisholm to take third and Volpe second.

That paid immediate dividends as Trevino grounded out to shortstop, with Chisholm scoring from the back door to tie the game.

The Rangers then brought on lefty reliever Andrew Chafin and pulled their infield in, but Alex Verdugo blooped the first pitch he saw over second baseman Marcus Semien to score Volpe for the 2-1 lead.

Volpe added a clutch two-out, two-run single in the eighth inning to give the Yankees some more breathing room, a rally that was again keyed by Chisholm’s speed as he beat out an infield single to load the bases for Volpe.

But that only delayed the devastation.

In the bottom of the eighth, the Rangers staged a rally that began with a fielding error by LeMahieu on Josh Smith’s high chopper to first base.

Jake Cousins then allowed that run to eventually come in to score to make it 4-2 and then loaded the bases with one out, at which point Aaron Boone called on lefty Tim Hill.

Nathaniel Lowe hit a sacrifice fly that pulled the Rangers within 4-3 but Hill got pinch-hitter Jonah Heim to strike out to leave the tying run on third base.

Rodon was dominant against the Rangers, allowing only one hit while walking two and hitting a batter.

The left-hander recorded six of his 11 strikeouts on his slider on a night when he generated 19 whiffs — 10 on the slider. Three of his punch-outs caught the Rangers looking.