Atlanta - Reigning US Open champion Rory McIlroy of Northern Ireland suffered an injury to his right forearm on Thursday after hitting a ball near a tree root in round one of the PGA Championship.
McIlroy was in the trees on the third hole and blasted a shot that snapped the club and left McIlroy in pain. He wrapped ice in a towel and placed it on the inside of his right arm near the wrist.
After a bogey at the third, McIlroy played on and made par at the par-3 fourth, then blasted a tee shot at the par-5 fifth, having placed the ball on the tee with his left hand, unusually.
McIlroy led the Masters entering the final round but a woeful back-nine cost him a chance at the green jacket last April.
That collapse helped him know what to do to hold onto a late lead two months later and win his first major at Congressional Country Club near Washington.
McIlroy, who had shared third in his two prior PGA Championship starts, began the week among the favourites on an Atlanta Athletic Club course that played to his strengths.