Don't know who this kid is ... but ya might wanna keep an eye on him -- 'cause the youngster took Porzingis to the hole TWICE during a 1-on-1 session Wednesday ... and we've got the video! 

The whole event was pretty awesome ... the NY Knicks star took the court against a bunch of kids at the Delta "Fly Like a Pro" event at the Chelsea Piers. 

Porzingis dominated most of the kids (some kids hit from downtown) ... but this one kid turned some heads by shooting over the 7'3" superstar two different times! 

Impressive stuff.