Kylie Jenner and Timothée Chalamet finally hit the red carpet together after two years of low-key romance -- and it was pure fashion fireworks from start to finish.

The genetically blessed duo oozed A-list glam in coordinated looks as they strolled in hand-in-hand at the 70th David Di Donatello Awards in Rome, where the photogs were basically foaming at the lens.

Kylie stunned in a curve-hugging black Schiaparelli gown, while Timothée rocked a sleek velvet suit -- and the two were not only matching, but practically glued at the hip.

It was full-on couple goals -- Timothée leading the way with his hand snug around Kylie’s hip, low-key marking his territory ... and judging by her smitten smile, she was all for it.

No doubt, this was a major moment -- officially sealing the deal they’re in it for the long haul, after keeping things pretty low-key since they first sparked romance buzz two years ago.