Cardi B says Nicki Minaj questioning her parenting skills triggered their clash during New York Fashion Week.
The 25-year-old rap star - who has a two-month-old daughter called Kulture with fellow rapper Offset - has revealed the background to their much-discussed clash last month, when their simmering rivalry took a violent turn.
Cardi said: "For a while now she's been taking a lot of shots at me. I spoke to her twice before, and we came to an understanding. But she kept it going."
The 'Bodak Yellow' hitmaker has claimed their skirmish was ignited after Nicki liked - and then unliked - a tweet about her parenting.
Cardi told W magazine: "I was going to make millions off my Bruno Mars tour, and I sacrificed that to stay with my daughter.
"I love my daughter. I'm a good-ass f***ing mom. So for somebody that don't have a child to like that comment?
"So many people want to say that party wasn't the time or the place, but I'm not going to catch another artist in the grocery store or down the block."
As well as recently becoming a parent, Cardi also married Offset in 2017.
But the chart-topping star has admitted she previously doubted whether they could sustain a marriage because of their jam-packed work schedules.
She shared: "When I got married with my dude, we still had a lot of doubts, because our relationship is not like everybody's.
"He was always travelling, and I was always travelling. We're artists.
"So I used to see him, like, twice a week, and, you know, he's known for having different women, and I'm known for, like, not taking s**t from guys. But we really loved each other, and we was scared to lose each other."