GULLANE, SCOTLAND (REUTERS) - Phil Mickelson suddenly has the world No.1 ranking in his sight after what he said was the best round of his career took him to a superb British Open victory at Muirfield on Sunday.

The American, who burst from the pack to win by three shots after a sizzling last round of 66, climbed above Northern Ireland's Rory McIlroy into second place in the world rankings behind Tiger Woods who is still comfortably ahead.

Mickelson has never topped the official world rankings, which were introduced 24 years ago.