That was in 2000 after he won the U.S. Open.
there are 6 national tennis association in the world.
Lleyton Hewitt (19th November 2001)
At the moment Andy Murray.
Martina Hingis was 16 years, 6 months old when she gained the #1 ranking in women's tennis in March, 1997.
currently Roger Federer is the world's number one men's tennis player, followed by Nadal and Djokovic
Pete Sampras, a professional tennis player, was ranked as the world's number 1 tennis player in 1993. He held that position for nineteen consecutive weeks.
at the moment it is robin soderling