The performance began with Cooper standing alongside a piano, which Lady Gaga began to play about a quarter through.
Lady Gaga takes the opportunity to whip out a second gown at the 2019 Oscars.
In the final 20 seconds of the song, as Gaga and Cooper sang together at that handsome Steinway piano, you could have heard a pin drop. The duo performed the song in an electrifying performance earlier in the night.
The ANI report also stated that Lady Gaga is the first celebrity to wear the Tiffany diamond after Audrey Hepburn, who wore it during a photoshoot of her 1961 film Breakfast At Tiffany's. But it was the hefty yellow bauble around her neck that stole her look.
She told the audience: "Thank you so much to the Academy for this wonderful honour".
She said: "What I would love to say is one of the hardest things in life is to be fearless enough to be yourself".
"There's not a single person on the planet that could have sang this song with me but you".
They started the year with a cameo at the Golden Globes, where Cooper wore a white tux and Shayk stunned in a gold body-hugging sheer dress.
Ronson gave a hat tip to fellow collaborator Gaga for her being the one-woman army that she is. "You can't convince me that lady gaga and bradley cooper aren't dating sorry", wrote Twitter user @jtrumps_. She then went on to call the Gaga tune "Born This Way" "reductive". She sang solo as Cooper attended the BAFTA awards, which were held on the same night.
It was only in December that Madonna, 60, appeared to take a dig at Gaga's oft-quoted press tour line, in which she said of costar Bradley Cooper, "There can be 100 people in a room and 99 of them don't believe in you, but all it takes is one". "I have an incredible director and friend and lead actor, and I had him by my side the whole time and we did it".