Serena Williams took on Madonna this weekend ... not on the court (because she would smash Madge's face in) .... but at a Karaoke bar in Milan, where she belted out "Like a Prayer" ... like a CHAMP!
Serena and her sister Venus were in the country for an exhibition tennis match -- but Saturday night, the two partied their well-endowed asses off ... singing and dancing like maniacs.
The next day ... Venus suffered a wardrobe malfunction during a match with an Italian player ... but managed to cover up before anything got loose.
Venus & Serena Williams
We Can SING Like Madonna!
12/5/2011 9:00 AM PST BY TMZ STAFF
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