Serena Williams withdraws from Madrid Open with flu

(Reuters) - Women's world number one Serena Williams has withdrawn from the Madrid Open because of flu, the organizers said on Friday. "Unfortunately, I have to withdraw from Madrid because I've been battling the flu and I'm not at 100 percent. I look forward to returning soon," Williams said in a statement. Agnieszka Radwanska is now the top seed at the tournament staring on Saturday. (Reporting by Simon Jennings in Bengaluru; editing by Amlan Chakraborty)