LOUISVILLE Kentucky (Reuters) - Rory McIlroy, seeking his fourth major title, ended a pulsating third round of low scoring and frequent lead changes to preserve his one-shot advantage at the PGA Championship on Saturday.
A stroke in front overnight heading into what is traditionally known as 'Moving Day', the British Open champion birdied three of the last four holes on a receptive, rain-sodden Valhalla Golf Club layout to card a four-under-par 67.
McIlroy, who is in pursuit of a third consecutive victory on the PGA Tour, fended off a series of challenges to keep his position at the top of a tightly congested leaderboard as he posted a 13-under total of 200 in the year's fourth and final major.
Austrian Bernd Wiesberger, one of six players who held at least a share of the lead in a wildly fluctuating third round, was alone in second place after matching the day's best score with a 65.
"I didn't expect any of this really coming into this week," Wiesberger, a two-time winner on the European Tour, told reporters after ending his round with three successive birdies. "I knew I was prepared well and the course really suits my eye.
"So far I've taken advantage of this and it's great to finish the round with three birdies in a row, and basically tap-in birdies as well.
"That gives me hopefully good momentum going into tomorrow. It's a new situation for me in a major championship."
American 'young gun' Rickie Fowler, a top-five finisher at each of the year's previous three majors, was at 11 under after firing a 67 with 2005 PGA Championship winner Phil Mickelson (67) and Australian Jason Day (69) a further stroke adrift.
Former British Open champion Louis Oosthuizen of South Africa (67) and Swedish world number four Henrik Stenson (67) were among a group of four at nine under on a high-quality leaderboard that sets up an intriguing battle for the title.
However, most eyes in Sunday's final round will be focused on McIlroy, who has produced spectacular form over the past month and came into this week as an overwhelming favourite.
The 25-year-old Northern Irishman completed a wire-to-wire victory at last month's British Open before winning the WGC-Bridgestone Invitational last Sunday in his next start.
Reporting by Mark Lamport-Stokes; Editing by Gene Cherry