winning four majors in the same year, what seemed inevitable to the world number one until a little known italian roberta vinci, rachged just 43 in the world. i m happy. i don t know. it s tough to explain my emotion right now. i thought she played the best tennis in her career. she played literally out of her mind. reporter: williams wasn t the only one shocked to see the unseeded player put an end to her 33-match winning streak. this is one of the hugest upsets in tennis history. roberta had not beaten serena in four tries. reporter: for williams it was an exhausting week, battled her sister on tuesday and after that admitted to being tired. wake up early to practice. reporter: williams has been a fan favorite. a cinderella story out of the rough streets of compton, california. she s won the so-called serena slam, four majors in a row, just not in a calendar year, something she pointed out to
many stunned people in one place. i talked to all the experts before the match. they said there was no scenario in which serena williams would have lost that match. the italian didn t think she stood a chance, but then she stunned everybody including herself. she s done it. an extraordinary upset! reporter: for serena williams, it was the end of a year-long quest. italy s roberta vinci ends serena william s run. two matches away from the rare calendar grand slam, winning four majors in the same year, what seemed inevitable to the world number one until a little known italian roberta vinci, ranked 43 in the world. i m happy. i don t know. it s tough to explain my motion right now. i thought she played the best tennis in her career, she played literally out of her minds. williams wasn t the only one
reporter: for serena williams, it was the end of a year-long quest. italy s roberta vinci ends serena williams grand slam run. i don t want to talk about how disappointing it is for me. reporter: just two matches away from the rare calendar grand slam winning four majors in the same year. what seemed inevitable to the world number one until a little-known italian, roberta vinci, ranked just 43 in the world. i m happy. i don t know. it s tough to explain my emotion right now. i thought she played the best tennis in her career. she played literally out of her mind. reporter: williams wasn t the only one shocked to see the unseeded player put an end to her 33-match winning streak. this is one of the hugest upsets in all of tennis history. roberta vinci had not beaten serena williams in four tries. reporter: for williams, it was an exhausting week. she battled her sister venus on tuesday and after that matched a mitted to being tired. i have to wake up early to