体坛英语新闻：Serene Williams withdraws from Madrid Open

MADRID, April 29 (Xinhua) -- World No. 1, Serena Williams has pulled out of the Mutua Madrid Open tennis tournament which begins here on Friday.

The 2013 and 2014 champion withdrew from the competition, citing illness as the cause of her absence.

The news means that Poland's Agnieszka Radwanska replaces the American as the top seed in the competition, while Spain's Gabine Muguruza is now third seed.

Meanwhile Spanish No. 1, Rafael Nadal gave a press conference in Madrid on Friday in which he defended his decision to take legal action against former French Minister of Sport, Roselyne Bachelot over doping accusations.

"The time has come to say 'enough is enough'," said Nadal, who added he was "totally recovered" from recent physical problems and "enjoying training and competition."