Wimbledon: Serena survives, Del Potro sets up Nadal clash

For 35 minutes on Centre Court Serena Williams was knocked off her stride by a feisty Italian who looked as though she had ripped a page from the American's tennis manual. Playing in her first Grand Slam quarter-final, unseeded Camila Giorgi went toe-to-toe with the seven-time champion and became the first player to take a set off her so far. Williams raised her intensity level, added some velocity to her groundstrokes and some decibels to her growls and powered back to win 3-6 6-3 6-4 -- a scoreline that was a touch closer than what actually transpired on court. Serena Williams was the lowest-ranked player ever to reach a Wimbledon quarter-final. Her ranking is 181. (Video: SNTV).