The wild incident happened in the fourth quarter of Golden State's Game 2 matchup with the Kings in Sacramento ... when Green got tangled up with Domantas Sabonis following a missed basket.

You can see in video of the play ... Sabonis crashed to the ground while trying to position himself for a rebound -- and he landed near Green's legs.

Sabonis then made a clear attempt to hold Green's right ankle -- and in response, Draymond kicked down right on the Kings star's sternum.

Sabonis screamed out in obvious pain -- and refs stopped the game immediately. They would go on to review the play.

But, as they checked out replays of the incident ... Green got into it with fans, who trash-talked him and flipped him off.

Eventually, refs hit Sabonis with a technical foul for grabbing Green ... but tossed the Warriors forward from the game, determining his stomp was worthy of a flagrant 2.

The Warriors went on to lose without Green -- who appeared pissed over the call afterward.

"My leg got grabbed," the 33-year-old said. "Second time in two nights. Referees just watched it. I gotta land my foot somewhere. And I'm not the most flexible person. So that's not stretching that far."

For Sabonis' part, he ripped Green for the play, telling reporters, "There is no room for that in our game today." He required X-rays ... but, reportedly, he avoided injury.

Green is no stranger to controversy -- especially this season ... you'll recall, he stepped away from the Warriors for several days in October after socking his teammate, Jordan Poole, during a practice.