Malaysia's Nicol David has passed another major milestone in her illustrious squash career by moving into her 45th successive month at the top of the April Women's World Squash Rankings, published today by the Women's International Squash Players' Association (WISPA).

By overtaking the 44-month run achieved by Australia's Michelle Martin in October 1996, Nicol David has established the longest unbroken reign as world number one since the great New Zealander Susan Devoy 17 years ago in February 1993.

The 26-year-old from Penang began her 2010 WISPA World Tour campaign in March, and immediately added a further two titles to her formidable collection by winning both the Chennai Open in India and the CIMB KL Open on home soil in Malaysia - successes which brought her career WISPA title haul to 43.

England's Jenny Duncalf, runner-up to David in KL, reclaims her career-high world number two ranking while Dutch star Natalie Grinham, currently out of action while awaiting the birth of her first child, drops to third place.

But England's Alison Waters rises a single position to record a best-ever fourth place in the new list. The 26-year-old Londoner is enjoying the form of her life after winning two WISPA Tour titles in the USA at the beginning of the year before becoming the British National champion for the second time in February.

Mexico's Samantha Teran celebrates her third rankings rise this year by moving to a career-best No12 this month. Unseeded, the 28-year-old from Mexico City reached the quarter-finals of the KL Open in Malaysia.

Lower in the list, Australia's Donna Urquhart makes her long-awaited debut in the world top 20 at No20. The 23-year-old left-hander from New South Wales reached her ninth Tour final at the Chairman's Cup in Hong Kong as third seed in January, then earned places in the main draws of both the Chennai Open and KL Open as a qualifier.

And just outside the top 20 is a trio of promising stars all boasting career-high rankings - England's Sarah Kippax at 21; ahead of Malaysian Delia Arnold, up seven places to 22; and New Zealander Joelle King at 23.

April top 20 (inc. points average):

1 [1] Nicol David MAS 2897
2 [3] Jenny Duncalf ENG 1575
3 [2] Natalie Grinham NED 1485
4 [5] Alison Waters ENG 1443
5 [4] Rachael Grinham AUS 1421
6 [6] Omneya Abdel Kawy EGY 1214
7 [7] Madeline Perry IRL 974
8 [9] Laura Massaro ENG 848
9 [8] Natalie Grainger USA 643
10 [10] Kasey Brown AUS 636
11 [11] Camille Serme FRA 618
12 [13] Samantha Teran MEX 576
13 [12] Vanessa Atkinson NED 506
14 [14] Engy Kheirallah EGY 501
15 [17] Jaclyn Hawkes NZL 479
16 [15] Raneem El Weleily EGY 475
17 [19] Rebecca Chiu HKG 430
18 [16] Annie Au HKG 425
19 [18] Isabelle Stoehr FRA 416
20 [21] Donna Urquhart AUS 413