And the pair looked very much together, hugging closely as they posed on the red carpet for photographers.
Rita, 23, was stunning in a bright green sequined Lanvin dress, accessorising with a metallic mini clutch bag and strappy sandals.
The blonde bombshell channelled screen siren Marilyn Monroe with beautiful bouncing curls, and finished her stylish look with smoky eye make-up with babydoll pink lips.
Calvin, meanwhile, made a handsome date in a black suit, a crisp white shirt and bow tie.
The night before, the How We Do singer was spotted holding hands with her DJ boyfriend while heading to a Pre-Grammy party at 1 Oak in West Hollywood.
There, the couple partied alongside the likes of Rihanna and Drake following Jay Z's Roc Nation pre Grammys brunch earlier in the day.
Rita opted for a casual yet sexy look, wearing a navy suit jacket that revealed her toned legs, slicked-back hair and a splash of red lipstick while Calvin went for a suit that he pared down with a casual black top.
Rumours that the couple had split after just nine months surfaced earlier this month when the How We Do singer stopped following Calvin on Instagram.
A cryptic message on the image-sharing website soon followed: "Have you ever wondered which hurts the most: Saying something & not wishing you had not, or saying nothing and wishing you had?" wrote the star.