Rory McIlroy fights to stay in touch as Lee Westwood's challenge falls apart

Rory McIlroy was battling to remain in touch with Dustin Johnson in the fight for the world number one spot as Lee Westwood's bid for victory disappeared in the £7.9million WGC-Mexico Championship.

Westwood, who has played in 56 of the possible 61 individual World Golf Championship events without success, was within a shot of the lead after birdies on the first and fourth at Chapultepec Golf Club.