Dato' Nicol has been number one in the world for almost five years and in 2010 she was unstoppable.  She is currently ranked world number1 in women's squash, and is the first Asian woman to achieve this. She won the British Open title in 2005, 2006, 2008, and 2012, as well as the World Open title a record 6 times in 2005, 2006, 2008, 2009, 2010, and 2011.

David is the first squash player to have won the World Junior title twice; in 1999 and 2001. David joined WSA (Women’s Squash Association) and turned professional in 2000 when she won her first WISPA title, after only a month on the tour. The victory came in February, when she won the Savor Finnish Open. David was also invited to carry the Olympic torch for Malaysia during the buildup to the Athens Olympics in 2004 and being appointed as National Goodwill Ambassador for Malaysia.

David's other notable achievements include the Asian Squash Championship, which she won a record eight times (in 1998, 2000, 2002, 2004, 2006, 2008, 2010 and 2011). She also held a 13-month, 51-match winning streak, from March 2006 until April 2007, when she finally lost to Natalie Grinham in the final of the 2007 Seoul Open.October 2010 saw David collect the only title that was eluding her. At the Commonwealth Games, David finally claimed the biggest title in squash “Gold Medal”.

David has also obtained the WSA Player of the Year on six consecutive occasions, from 2005 until 2010.