England's Luke Donald has been confirmed as world number one for the first time following his win in PGA Championship at Wentworth on Sunday.
He takes over from compatriot Lee Westwood whom he beat in a play-off to win the prestigious European Tour title.
Westwood drops down to second with Martin Kaymer of Germany, who has also filled the top spot this year, in third.
The situation at the top is likely to remain fluid at least until the year's second major, the US Open, is played at Congressional Golf Club in Washington DC from June 16-19.
Former top-ranking player Tiger Woods, currently recovering from injury, continued his slide and is now in 13th position, the fifth-ranking American.