Serena Williams and Maria Sharapova 'Rumbles' outside the Tennis Court

Maria Sharapova's rivalry with Serena Williams has left the tennis court and gotten SUPER personal ... and today Sharapova delivered an overhead smash about Serena's dating life for all the world to hear.

Serena fired the first shot in a Rolling Stone interview recently where she ripped on
Sharapova (she didn't mention Maria by name, but the interviewer assumed it was her) by saying, "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."

FYI -- Maria is dating one of Serena's rumoured exes.

In a pre-Wimbledon press conference today, Sharapova took out her claws and got catty ... bringing up the fact that Serena is rumoured to be dating her tennis coach (who is possibly still married).

Lets term this one Act 1 Scene one....will you posted on further developments on this isssshhh...