Lizzo initially hinted that she was working on something with SZA back in November.
"There's something exhilarating about the challenge of it all," the star said of her upcoming performance.
The former couple announced they were expecting a baby in November 2022.
The singer performed Prince's "1999" with purple lights raining down on her -- because, of course.
"Testimony" will drop before the full album is released later this year.
Warwick's timeless breakout smash was penned by the legendary songwriting team of Hal David and Burt Bacharach, the latter of whom died at 94 this week.
The peerless composer wrote smashes for Dionne Warwick, Dusty Springfield, Carpenters, Herb Alpert and many more.
The Memento Mori precursor's debut came along with its black-and-white music video.
"A lot of people go through this, and they go through it in silence," the singer said on the Jennifer Hudson Show.
The celebrated pop composer died Feb. 8 from natural causes.