Rihanna wasn’t about to stay shut out -- after her bodyguard let a door hit her in the face, she fired off a perfect clapback, all caught on cam!

The singer was stepping out of NYC’s Four Seasons on Friday when a door swung straight into her face as her bodyguard strolled right on ahead -- prompting her to laugh it off and clap back, "Such a gentleman you are!"

TBF, he wasn’t totally checked out -- he just seemed way more focused on the pack of paps rushing in and forgot Rihanna was right behind him.

The video’s already making the rounds online -- and yeah, no clue if the bodyguard’s cringing over that door-slam fail.

One thing’s clear though ... Rihanna can handle herself, and no door’s bold enough to shut her down!