Nik Richie vs. Dan Bilzerian -- Epic Cake Beatdown ... One Step Closer to Boxing? (VIDEO)

Internet playboys Nik Richie and Dan Bilzerian have been trading barbs online for months and they finally came to blows Wednesday night … well, not really … but it's hysterical anyway.

Richie was celebrating his birthday at Surrender Nightclub in Encore at Wynn Las Vegas when the club brought him out a birthday cake … with Bilzerian's bearded mug on it.

Rather than blow out the candles and cut the cake, Richie put on a pair of boxing gloves and pummeled it.

NR and DB have been going back and forth for months about fighting -- Nik wants a boxing match, Dan wants it MMA. The stakes? In the hundreds of thousands of dollars.

Bilzerian tells TMZ, "If I ever got a birthday cake with another dude on it, so I could hit it with a boxing glove after I had refused to fight him for 200K, I'd know I lost at life."