Former american

Paris Olympic Games: Former American tennis star Serena Williams has paid tribute to Rafael Nadal with a touching video after the 22-time Grand Slam champion retired from professional tennis.

A 92-time tour-level champion Nadal, who spent 209 weeks at No. 1 in the ATP Rankings, wrapped up his glittering two-decade-long tennis career with a loss in his country's Davis Cup quarterfinal tie against the Netherlands.

He retired as second in the men's standings for most Grand Slam titles with 22 majors, of which record 14 he won on clay court of Roland Garros.