The 28-year-old from Cairo first topped the world rankings in January - and held onto the position until Gaultier took over in November. But victory in the PSA Super Series Sky Open in his home city in September, and the 27th Tour final appearance of his career at the Qatar Classic last month, boosted Darwish's ranking points tally to see him overtake his French rival.
Heading the final PSA ranking list of the year rounds off a magnificent 2009 for Darwish who was also voted the 'PSA Player of the Year' at the World Squash Awards in London last weekend.
Amr Shabana might have expected to see out the year as world number one after becoming world champion for the fourth time last month after winning the Kuwait World Open title in style at the Green Island Resort. But the left-hander, whose 33-month reign as world number one was ended by compatriot Darwish in January, sustained a shoulder injury in Kuwait and was forced to withdraw from the Qatar Classic.
Shabana slips to three, just ahead of England's Nick Matthew, winner of the Qatar Classic, who holds onto fourth place.
Two players make six-place leaps in the top 20 – Egyptian Wael El Hindi to No10 and Englishman Daryl Selby to a career-high No11. After an indifferent first half of the year, El Hindi made it through to the quarter-finals of both the Sky Open and World Open against the seedings – and is now just two places away from his highest-ever ranking.
Selby, who began the year outside the top 30, has enjoyed an impressive recent run – reaching the quarter-finals of both the British Open and Hong Kong Open unseeded, and last week lifted the Dutch Open crown in Rotterdam as the fourth seed. The 27-year-old from Essex now becomes the fourth highest-ranked Englishman for the first time.
Egyptian teenager Mohamed El Shorbagy re-stakes his claim as the youngest player in the top 20 by re-entering the elite group at 20. The talent of the 18-year-old from Alexandria was recognised in London this weekend when El Shorbagy won the PSA Young Player of the Year award.
1[3] Karim Darwish EGY
2[1] Gregory Gaultier FRA
3[2] Amr Shabana EGY
4[4] Nick Matthew ENG
5[5] Ramy Ashour EGY
6[6] James Willstrop ENG
7[9] Peter Barker ENG
8[7] David Palmer AUS
9[8] Thierry Lincou FRA
10[16] Wael El Hindi EGY
11[17] Daryl Selby ENG
12[11] Adrian Grant ENG
13[12] Alister Walker ENG
14[17] Laurens Jan Anjema NED
15[15] Cameron Pilley AUS
16[13] Mohd Azlan Iskandar MAS
17[10] Borja Golan ESP
18[20] Stewart Boswell AUS
19[19] Ong Beng Hee MAS
20[21] Mohamed El Shorbagy EGY
Issued by Howard Harding on behalf of the PSA