Padraig Harrington returned to top form ahead of his defense of the PGA Championship with a six-under-par 64 to lead the Bridgestone International. The Irishman has endured a miserable year after reshaping his swing, but his first round showing at Firestone Country Club in Ohio showed his hard work may be paying off. “Compared to the first six months of the year it’s obviously my low score of the year, my best score of the year,” he told reporters.