It was a 12-second verbal attack that has played over and over for three days.
"It was a really tough point in the match and it was really close and got a really tough call that wasn't the correct call, and, you know, things got a little heated and I had a conversation with the line judge that didn't go so well," Williams said.
Williams, ranked No. 2 in the world by the World Tennis Association, said she does not recall moments of Saturday's incident but believes she apologized for her actions promptly and completely.