Only Tiger Woods, Greg Norman and Nick Faldo have spent more time as number one than McIlroy
Rory McIlroy from Northern Ireland has returned to number one place in the world for the first time in five years.
The four-time grand winner, 30, replaces American Brooks Koepka.
Neither player can be seen at the Pebble Beach Pro-Am this weekend, but the bi-annual classification of the ranking system takes McIlroy top.
This will be his 96th cumulative week as the world's number one – the fourth most of a player – but his first since September 2015.
Only Tiger Woods (683), Greg Norman (331 ) and Nick Faldo (97) have spent more weeks as & # 39; the world's best ranked player.
The complicated nature of the ranking system brings McIlroy from 0.2 points behind Koepka to 0.03 points in front.
Both players are scheduled to play at the Genesis Invitational in California, which starts Thursday.