Rather than walk on from backstage, the pair emerged from the crowd and walked up the steps where a piano was waiting for them.
As the performance came to an end, they received a standing ovation from the crowd.
However, unlike the crowd, our music critic – Alexandra Pollard – wasn’t too impressed.
She said: “There could be 100 people in a room, and only one of them is singing off key, and that’s Bradley Cooper. Actually, Lady Gaga also had a few wobbly moments performing her and Mark Ronson’s Oscar-nominated song “Shallow” from A Star is Born. She brought it back with a vengeance for the song’s climax, though, after which Cooper came and sat uncomfortably close and ruined it again.”
Winners at this year’s ceremony included Olivia Colman for The Favourite, Rami Malek for Bohemian Rhapsody, Regina King for If Beale Street Could Talk and Mahershala Ali whose film Green Book won Best Picture. Alfonso Cuarón took home Best Director for his Netflix drama Roma.
You can find a full list of winners here.
Earlier in the evening, Black Panther’s Hannah Beachler became the first black winner of the Best Production Design award, delivering an emotional speech that was praised by Angela Bassett and Reese Witherspoon.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies