Sugar Ray Leonard -- Boozy Anniversary Dinner ... Baller Gift and Kardashian Diss

Sugar Ray Leonard celebrated his 21st wedding anniversary like a BOSS last night -- expensive dinner, expensive gift ... and it all ended with a pretty funny dig at the Kardashians.

The clip is hilarious ... the couple was clearly in a SPIRITED mood on the way out of Katsuya in Brentwood (his wife Bernadette was especially happy) ... when we asked about the gift!

At first, Bernadette plays coy ... but ultimately spills the beans about the badass (and super thoughtful) gift Leonard gave her to celebrate the occasion.

And then came the Kardashian diss -- check out the video.