Sylvester Stallone Painting Sells for $410K at AIDS Research Gala

Sylvester Stallone may want to retire from acting and focus on painting full-time... 'cause one of his creations sold at an auction for AIDS research -- and made nearly half a million dollars.

The actor and his family hit a gala in support of amfAR -- a prominent AIDS research foundation -- at The Wynn Hotel in Las Vegas last night and, Sly brought a painting with him ... a multicolored Stallone original.

Check out the clip ... the auctioneer is asking if one of the warring bidders wants to one-up the current offer -- sitting at $410K!!!

The bidder turns down the opportunity... and, it sells to the other as people loudly applaud. The camera quickly flashes to Stallone's face -- who looks so excited his work could raise a ton for a great cause.

Check out the piece of art for yourself, called "Knocking Heads" ... full of vibrant greens, yellow and reds with faces deep in thought -- and a rendering of Sly as iconic character Rocky Balboa.

If you don't know ... Stallone's painted for years, so this isn't a novel work -- but, it's still a heck of a lot for someone who doesn't paint for a full-on living.

Stallone received an award at the gala, from Tommy Hilfiger and his wife Dee. We're told the event went well and was incredibly profitable for the organization.

BTW ... Sly was in a giving mood it seems -- 'cause he also auctioned off a spot in the next season of "Tulsa King" which went for another $300K.

Stallone may be a member of the "Expendables" ... but, his charity contributions were indisposable.