The singer-songwriter took the stage at Resorts World in Vegas Monday ... and, while outfitted in a tight black leather bodysuit, a dancer came up and ran his hands over Jackson's chest ... while Ms. Jackson looked ready to get 'Nasty' with it.

The Vegas pose calls back to the cover of her 1993 album "Janet," which showed Jackson facing the camera with her arms up in the air, with two hands cupping her bare breasts from behind -- the wide release only showed her from the neck up, but the limited edition featured the full photo. The image was also on the cover of Rolling Stone magazine that year.

But of course, with her dancer grabbing her in this performance -- it does also bring to mind the Justin Timberlake incident at 2004's Super Bowl XXXVIII.

If you don't remember -- but honestly, how could anyone forget? -- Janet performed with JT in Houston, Texas more than 20 years ago ... when, during a medley of their hit songs Justin ripped off part of Janet's costume. The move revealed Jackson's right breast and nipple covering.

In the wake of the incident, Janet dealt with all kinds of scrutiny, and it temporarily derailed her career ... and, JT never really stepped up to defend her. He eventually apologized to Janet in 2021 -- though, he sorta took it back earlier this year.

It's funny Janet's embracing this moment that nearly destroyed her career ... especially at the end of a year so tumultuous for JT -- who was arrested for DUI back in June and was the subject of public ridicule for his own wardrobe malfunction earlier this month.

Janet has turned her residency -- which kicked off yesterday -- into a family affair ... as eagle-eyed fans noticed her mom Katherine turned up to cheer her baby girl on.