Former World Numbers Ones Venus Williams and Caroline Wozniacki have stormed into the Singles Semi-final of Dubai Duty Free Tennis Championship.<br/><br/>In the quarter finals today, Venus Williams defeated Flavia Pennetta 6-3,7-5 in straight sets. Caroline Wozniacki beat S. Cirstea 6-2, 6-1 in another easy encounter.<br/><br/>In the other matches tonight, Reigning World Number One Serena Williams plays against Jelena Jankovich . Carlos Suarez Navarro takes on A Cornet in another quarter final.<br/><br/>In the Women's Doubles , unfancied duo of Raquel Kops-Jones and Abigal Spears caused the upset of the day as they sent tournament number one pair of Sarra Errani and Roberta Vinci packing 6-4,6-1 in straight sets.