Jordan Spieth's runner-up finish at the Singapore Open keeps him clear at the top of the world rankings as Rory McIlroy retook second spot from Jason Day.

Australian Day missed his first cut in eight months at Torrey Pines, while Northern Ireland's McIlroy did not play after finishing in a tie for third at Abu Dhabi two weeks ago.

Spieth opted to travel to Singapore as part of a hectic early-season schedule, and the American lost out by one shot to South Korean Younghan Song after a Monday finish to the final round.

Branden Grace showed once again that when in contention he is a very tough man to beat.

The South African took advantage of a Paul Lawrie collapse to win the Qatar Masters and is now closing in on the world's top ten.

By far the biggest mover in the top 20 was Farmers Insurance Open winner Brandt Snedeker.

The 35-year-old came back to win from five shots behind or more going into the final round for the fourth time in his career, and is up 12 places to 12th.

His stunning final round of 69 was over nine strokes better than the field average, and he waited on Monday to see Jimmy Walker and KJ Choi fail to force a play-off in another delayed event.

Official World rankings:

 1. Jordan Spieth (USA)          12.12pts

 2. Rory McIlroy (NIR)           10.32

 3. Jason Day (AUS)              10.21

 4. Rickie Fowler (USA)           7.74

 5. Bubba Watson (USA)            7.49

 6. Henrik Stenson (SWE)          7.41

 7. Justin Rose (ENG)             6.44

 8. Dustin Johnson (USA)          5.69

 9. Patrick Reed (USA)            5.00

 10. Jim Furyk (USA)              4.99

 11. Branden Grace (RSA)          4.90

 12. Brandt Snedeker (USA)        4.27

 13. Sergio Garcia (ESP)          4.19

 14. Zach Johnson (USA)           4.18

 15. Adam Scott (AUS)             4.13

 16. Kevin Kisner (USA)           4.10

 17. Brooks Koepka (USA)          4.01

 18. Louis Oosthuizen (RSA)       3.68

 19. Hideki Matsuyama (JPN)       3.67

 20. Danny Willett (ENG)          3.64
Source: AFP