Wanna see the best high school dunker you've never heard of??
Good ... 'cause cameras captured Eric Gaines in a regional championship game this weekend -- and the dude can FLY!!!!
He's just 6'1", 140 pounds ... but 18-year-old Gaines took over for his Lithonia H.S. squad in a game in Georgia this weekend -- dunking on EVERYBODY.
Gaines threw down a few monster slams that woulda made Zion Williamson jealous ... even at one-point cocking back a tomahawk that he slammed on some poor kid's head.
Bad news for Eric .