Jennifer Lopez still knows how to make an entrance … and she made a hell of one Tuesday night at the premiere for her new flick, “Office Romance.”

J Lo dropped jaws at The Egyptian Theatre in Hollywood … wearing a flowing black gown that gave the naughty optical illusion it was showing more skin than it actually revealed.

And if that wasn’t enough eye candy for fans … Jen sure seemed extra chummy with her on-screen love interest, Brett Goldstein, who she’s rumored to be dating in real life.

She’s been single for a while now … and looking as amazing as ever in some recently dropped thirst traps … so it makes sense that she was going to be wooed at some point.