Ariane Grande stunned the Coachella crowd on the first night of weekend #2 by taking the stage during Kygo's set ... and debuting her brand new single.
Grande's live performance Friday night of "No Tears Left to Cry" came just hours after she released the single ... her first new track since last year's Manchester bombing. She also sang Marvin Gaye's "Sexual Healing" with Kygo during her surprise appearance.
It was her second live performance of the year -- she sang at the March for Our Lives rally in March as well.
As we reported ... Kygo dedicated his set to Avicii -- who was found dead at the age of 28 in Oman -- and ended it by playing the world-famous DJ's song, "Without You."