In an astonishing attack on the world number one, which comes just two days before Wimbledon gets underway, Sharapova told Williams to keep her opinions to herself as the bitter relationship between the two was laid bare.
Williams, the 16-time Grand Slam title-winner, was forced to apologise for her comments regarding the rape of a 16-year-old girl by two high school American football players in the Ohio town of Steubenville.
"I was definitely sad to hear what she had to say about the whole case," said Sharapova, who was defeated by Williams in the French Open final earlier this month.
"I just think she should be talking about her accomplishments, her achievements, rather than everything else that's just getting attention and controversy."
Sharapova, who has not beaten her great rival since 2004, also criticised Williams's love life after the American had aimed a thinly-disguised jibe at the Russian's affair with Bulgarian player, Grigor Dimitrov, believed to be a former Williams boyfriend.
"There are people who live, breathe and dress tennis. I mean, seriously, give it a rest," Williams told Rolling Stone magazine without naming the Russian.
"She begins every interview with 'I'm so happy. I'm so lucky' -- it's so boring. She's still not going to be invited to the cool parties. And, hey, if she wants to be with the guy with a black heart, go for it."
Sharapova, clearly upset at the insinuation, hit back on Saturday at Williams's romance with her French coach Patrick Mouratoglou.
"If she wants to talk about something personal, maybe she should talk about her relationship and her boyfriend that was married and is getting a divorce and has kids," said Sharapova.
"Talk about other things, but not draw attention to other things. She has so much in her