And although they had only performed Shallow together outside of A Star Is Born on one other occasion, Gaga and Bradley truly brought the chemistry to the stage that landed both of them nominations for their acting at this year's Oscars.
At Gaga's crescendo, Cooper rose, moved his microphone stand behind the piano, and sat beside Gaga and sang over her shoulder into a single mic.
Lady Gaga won Best Original Song Oscar for Shallow.
While the HBO show is nothing to be sniffed at, Bradley, 44, had a small part in the show - a contrast to performing with Lady Gaga at the Oscars on Sunday night.
In the initial moments of her acceptance speech, an emotional Gaga spoke with a staccato with tears streaming down her face and thanked the Academy, Ronson and Wyatt, her sister and her family.
On the red carpet, top five most talked-about Oscars fashion looks on Facebook were: Billy Porter wearing a Christian Siriano tuxedo dress; Jason Momoa's pink velvet tux and matching scrunchie; Jennifer Lopez's mirror-mosaic gown; Lady Gaga's 128-carat Tiffany diamond necklace; and Spike Lee's custom metallic-gold Jordan 3 sneakers.
'Period. End of Sentence' wins Oscar for Documentary Short Subject
It is about the rural women in a particular village in India who led a revolution against the taboos related to menstruation . Monga said she is "honoured and absolutely humbled to partner with Melissa and Rayka in making our short documentary happen".
Roger Goodell options to punish Robert Kraft if guilty
In the meantime, Kraft has maintained his innocence, as a spokesperson for the owner said, "We categorically deny that Mr. Irsay told a judge he was under the influence of painkillers when the traffic stop occurred.
Mahershala Ali wins supporting actor Oscar for 'Green Book'
Ali began his acting career in 2001, appearing as a doctor on television series "Crossing Jordan". Ali paid tribute to Dr Shirley, saying all he tried to do was to capture his essence.
"I think when you're in the room with this person, you don't have to do too much". Thank you for believing in us.
'There's a discipline for passion, and it's not about how many times you get rejected or you fall down or beaten up, it's about how many times you stand up and are fearless.
She continued, "I've worked hard for a long time, and it's not about, you know, it's not about winning".
Gaga made history at the 91st Academy Awards as the first person to ever receive a nomination for Best Actress and Best Original Song in the same year.