PARIS, France --
Novak Djokovic has been forced to withdraw from his French Open quarterfinal against
Casper Ruud due to the knee injury he aggravated in his fourth round win.
The move ends his title defense and means he will relinquish the No. 1 ranking.
The tournament announced the news, saying Djokovic has a torn medial meniscus in his right knee. The extent of the injury was found during an MRI exam.