Teyana Taylor got into a heated confrontation moments after the Oscars wrapped ... and TMZ has learned it all started after a security guard put his hands on her.

Sources with direct knowledge tell us the incident happened seconds after the Sunday night broadcast ended, as she was attempting to head back onstage for the Best Picture photo with her "One Battle After Another" costars.

According to our sources, Taylor was trying to return to the stage alongside Pam Abdi, co-head of Warner Bros., when a security guard attempted to stop them from going up the stairs.

Our sources say the guard used his body to block Taylor and put his hands on her, trying to physically hold her back and push her away from the stage to prevent her from getting past him.

In video from inside the Dolby Theatre, you can hear Taylor confronting the guard, telling him not to put his hands on a woman and calling the move very rude. At one point, she's heard telling people nearby, "He literally shoved me."

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Our sources say the moment quickly became tense as the guard continued trying to control access to the stage, and at one point asked Taylor to apologize during the exchange.

We've reached out to reps ... so far, no word back..