Former world's no.1 Maria Sharapova fired back at Serena Williams during the Pre-Wimbledon press conference, advising the American netter not to get personal and avoid controversial issues off the court.

Williams, who's coming off a straight set pummeling on Sharapova in the finals of the French Open, launched a barrage of verbal lashing towards an unnamed player in a feature article found in the latest edition of Rolling Stone Magazine. Williams called the player not cool and boring - a description that the author of the article believes directed at Sharapova.

Here's an excerpt taken from Williams' latest article in Rolling Stone:

"There are people who live, breathe and dress tennis. I mean, seriously, give it a rest." Serena exits the car and the conversation moves on to a top-five player who is now in love. "She begins every interview with 'I'm so happy. I'm so lucky' - it's so boring," says Serena in a loud voice. "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."

The 26-year-old Sharapova was clearly not happy about Williams' comment, prompting the launch of her own verbal attack at Williams.

"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," Sharapova told ESPN. "Talk about other things, but not draw attention to other things. She has so much in her life, many positives, and I think that's what it should be about."

Williams is rumoured to be romantically linked to tennis coach Patrick Mouratoglou, who recently got divorced.

Sharapova's current fling apparently is somewhat related to Williams. Grigor Dimitrov is apparently the one called the man with a black heart. The Bulgarian tennis player is rumoured to be one of the exes of the 16-time Grand Slam champion.