Post Malone Hurts Himself in Epic Backflip Fail on Live Stream

Post Malone fell flat on his ass on the floor attempting to backflip off a chair Monday ... slightly painful, unintentionally hilarious, all caught on camera during a live stream.

Watch the video ... in the middle of a Twitch stream with xQc, the Grammy-nominated artist warns, "This is just an attempt," before climbing onto his chair.

Before he can even properly push off the chair to start a flip, PM falls sideways right on his bottom.

He admitted, "I actually hurt my wrist." ... and -- no doubt -- his pride.

The singer went on to blame it on the chair, saying it rotated.

Ummm ... that's not the only thing that went wrong there, bud.

The "White Iverson" rapper has been having a hard time staying upright lately.

He had an even more embarrassing oopsie during a concert in India earlier this month. While heading down the stairs of the stage after his set in Khanapara, he missed a step and tumbled backwards right onto his booty.