Rihanna's turning up the heat in her new clothing drop ... looking absolutely savage in a red hot set of underwear from her latest Savage X Diesel collab.

RiRi's clothing line worked with Diesel on new lingerie, and she's showing off the goods ... with a heavy emphasis on fishnets.

Rihanna's modeling a few of her new offerings ... with a foiled fishnet bustier up top, and a foiled fishnet string bikini panty down below.

She's leaving little to the imagination here, and showing off some of her tattoos as well.

Rocking matching red hair, Rihanna's keeping the party going with some foiled fishnet thigh-high stockings ... and she's got a foiled fishnet maxi slip-on dress halfway down her waist.

RiRi added a furry blue and white jacket for the promo shoot ... but as far as we can tell, that ain't for sale.