Bad Bunny and Post Malone were fan faves at the kickoff of Coachella on Friday night ... but their performance suffered a brief hiccup, although it didn't put a damper on the mood.

Bunny brought Post out on stage during his two-hour show in the hot desert of Indio, CA, and the packed crowd just went berserk.

The superstars were playing acoustic guitar versions of Bunny's hits, "La Cancion" and "Yonaguni," when Post's mic suddenly went dead.

Check out video, obtained by TMZ, showing Bunny singing into a mic -- which was working just fine -- as Post was strumming his guitar, which was barely audible due to the technical difficulties. But, the two just kinda laughed it all off as the sea of fans began singing a capella to fill the unusual void on stage.

Despite their best efforts, they couldn't get Post's mic back up and running, and he made a graceful exit as Bad Bunny polished off his near-perfect set.

At another point during Bad Bunny's performance, there was another slight mishap. Post was dancing around the stage and took a little spill, but recovered nicely.

All in all, it was an exceptional performance by the two musical giants. And this surely won't be the last time we see them working together.