The comedian -- who was back in the hosting seat again -- ran through a pretty zippy monologue that hopscotched over a lot of big celebs, including Harry Styles, Taylor Swift, Lizzo, Beyoncé and Adele ... the last of which he honed in on for an official introduction.

Check it out ... TN says he'd done his homework on tonight's nominees, and read somewhere that Adele had never gotten a face-to-face with the wrestler-turned-actor.

At first, Trevor made it seem like he didn't actually have Dwayne on hand, but then trotted the dude out anyway -- which totally caught Adele by surprise. She got up and gave him a hug/kiss ... and DJ even plopped himself down at her table as the camera panned away.

When it comes to the other jokes ... he said Harry Styles was in the unique position to have panties thrown at him onstage and possibly wear them afterward, and he also jabbed at Taylor Swift by flipping her 'Anti-Hero' song on its head ... while taking a shot at Southwest.

Trevor also made sure to point that Queen Bey is on the verge of history ... she's up for a record number of Grammys, and stands a chance to win the most ever tonight too.