NY Mets BOOZY CELEBRATION ... Poppin' Bottles with WWE Belt

It's the kind of celebration that would make Stone Cold Steve Austin proud -- the NY Mets turnin' up by chuggin' beer and raising a WWE-style championship belt after winning the NLCS!

Check out the video ... you can see stars like Jacob deGrom and Daniel Murphy bathing in suds in the Mets locker room moments after putting the Cubs out of their misery.

Even manager Terry Collins got in on the action -- poppin' champagne and spraying down the fans who made the trip to Wrigley.