Donald, who is now guaranteed to occupy the No. 1 position heading into the Masters next month, backed his European Ryder Cup teammate to maintain his challenge at the top of the sport.

CNN: Donald dispels doubts to regain top spot

Northern Ireland's McIlroy, who will play for Europe against Snedeker in the Ryder Cup later this week, saw his challenge fade early on.

CNN: Snedeker scoops $10m jackpot

There were no such problems for the evergreen Perry, who is producing his best form late in his career, starring in the U.S. Ryder Cup triumph at Valhalla and mounting a strong challenge for his first major at the age of 48, making him the oldest Masters champion if he is successful on Sunday.

CNN: Perry and Cabrera leading after third round