- Vinci advances to fourth round
- Joined by Novak Djokovic, Madison Keys, Jack Sock
- Keys rallies from 5-1 third-set deficit
- Djokovic wins via retirement
(CNN)Unless she wins this US Open, Roberta Vinci couldn't possibly top last year's outing in New York. Twelve months ago the charismatic Italian with the throwback style pulled off one of the biggest upsets in tennis history by defeating Serena Williams in the semifinals.