His share of 13th place with, amongst others, James Kingston, saw him climb to 113th on the list, while Kingston, who had a shot at winning the event in which England’s Paul Casey triumphed, moved into the top 150 at 148th – the position he occupied at the beginning of the year.
Aiken closed to within three positions of Rory Sabbatini, who found himself in 110 on the list after his share of 44th in the Farmers Insurance Open at Torrey Pines in California.
The biggest South African climber in the rankings was James 'Jbe' Kruger, who moved inside the top 125 to 123rd from his previous week’s position at 131.
This came from his share of fourth in the Africom Zimbabwe Open, the rain-affected event won by Theunis Spangenberg for his maiden professional title.
Kruger, who was the 2010 champion in Zimbabwe, could have done with a fourth round in the rain-shortened 54-hole event. Had it run the scheduled 72 holes, he may have been able to reproduce his final-round pyrotechnics from last year to snatch a win.
In Bahrain, Aiken closed with a pair of 68s, his best scores of the tournament, after he opened with a 70, and reached halfway at five-under-par 137 with his second-round 69.
He made seven bogeys during the tournament, together with an eagle and 18 birdies.
Kingston, who was in contention for the victory throughout the opening three rounds, slipped to a closing three-over-par 75 to fall out of the top 10.
With three bogeys and a triple-bogey seven at the 17th on his card, the four birdies he achieved were not enough to keep him in the race.
Behind him, Richard Sterne, who has been battling a back injury over the last two years, had an encouraging tournament with his share of 30th, while Hennie Otto missed the cut.
South Africans in top 300:
11 Ernie Els
15 Retief Goosen
19 Louis Oosthuizen
22 Tim Clark
24 Charl Schwartzel
110 Rory Sabbatini
113 Thomas Aiken
123 Jbe Kruger
148 James Kingston
257 Keith Horne
271 Jaco van Zyl
282 Trevor Immelman
299 Hennie Otto