That's how the Washington Mystics spent their first few minutes as WNBA champions ... 'cause after they beat the Connecticut Sun, 89-78 Thursday, they went back to their locker room for some champagne dives!!!
The vid is hilarious ... the team sprayed down their clubhouse with a ton of booze -- and with a protective layer of plastic laid on the ground, they decided to get down on the floor.
Shatori Walker-Kimbrough and Natasha Cloud counted backward from 3 ... dove across the carpet -- and good times were had by all.
Of course, the celebration didn't end there ... the team continued boozing throughout the night -- and were even spotted capping off the evening at local D.C. nightclub!!!
As for prior to the party ... the Mystics kicked ass on the hardwood -- and they had some special courtside visitors for the historic Game 5 -- Wizards stars John Wall and Bradley Beal!!