Not all RBI doubles are created equal.

This one certainly wasn’t.

Diamondbacks shortstop Nick Ahmed hit a two-run double off a bounce — yes, off a bounce — in the fourth inning to give Arizona a 4-2 lead over the Cardinals on Tuesday night in St. Louis.

With the bases loaded and one out, Ahmed hit a that pitch Cardinals starter Jordan Montgomery spiked into the dirt and served a double into left, scoring Evan Longoria and Christian Walker as Jake McCarthy raced to third.

Ahmed was seen playfully shrugging after the crazy hit during a timeout after the play.

It didn’t get any better for Montgomery, who may have been a bit shaken after the unconventional double.

The former Yankee promptly allowed a three-run homer to catcher Gabriel Moreno, scoring McCarthy and Ahmed and giving the Diamondbacks a big 7-2 lead.

Montgomery, whose ERA ballooned to 4.84 after the drubbing, got out of the inning without further damage, but did not return for the fifth inning.

The Yankees traded Montgomery to the Cardinals before the trade deadline last season in exchange for Harrison Bader.

Though Montgomery has been inconsistent at times for the Cardinals, he’s been available.

As for Bader, he had a strong playoffs last season after returning from plantar fasciitis late in the Yankees’ season, which had kept sidelined since June before the Bombers traded for him.

The injury bug didn’t escape Bader this season either as the center fielder suffered a strained left oblique in spring training.

He is expected to miss at least six weeks for the Yankees.

As for Montgomery, he’s hoping not to get beat by anymore doubles hit off the ground this season.