Rafael Nadal

retained the world number one ranking
in men's tennis in the latest ATP list iassued on Monday but is under
threat of losing it to Roger Federer

as Wimbledon gets underway.

Nadal leads the way with 12,735 points from Federer (10,620) and
Briton Andy Murray (9,230), but has pulled out of the grass court
Grand Slam due to knee problems.

As a result, the title holder Nadal will lose 2,000 points in the
next rankings issued in a fortnight. The rankings take results of 52
weeks into account.

If Federer gets a sixth Wimbledon crown on July 5 he will be back
on top 11 months after being dethroned by Nadal, improving his points
tally by 600 points (losing 1,400 points as 2008 runner-up, but
earning 2,000 as champion 2009).

ATP top 10 as of June 22 (previous ranking in parenthesis):
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1. (1) Rafael Nadal, Spain, 12,735 points
2. (2) Roger Federer, Switzerland, 10,620
3. (3) Andy Murray, Britain, 9,230
4. (4) Novak Djokovic

, Serbia, 7,860
5. (5) Juan Martin del Potro, Argentina, 5,730
6. (6) Andy Roddick

, United States, 4,310
7. (7) Gilles Simon

, France, 3,970
8. (8) Fernando Verdasco, Spain, 3,620
9. (9) Jo-Wilfried Tsonga

, France, 3510
10. (10) Fernando Gonzalez, Chile, 3,165
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