ROCHESTER, United States (AFP) - Defending champion Rory McIlroy battled into contention at the PGA Championship with a birdie-birdie finish in Saturday's third round while leader Jason Dufner faltered and other challengers charged.

On a day when Oak Hill played havoc with much of the field, McIlroy fired a three-under par 67 to seize the clubhouse lead at three-under 207 for 54 holes at the US$8 million (S$10 million) event, the year's final major tournament.

McIlroy birdied the par-3 sixth, took his only bogey of the day to start the back nine, then birdied the par-5 15th and closed birdie-birdie on two of Oak Hill's most difficult holes.

There were only seven players ahead of McIlroy as Oak Hill took back much of what players gained Friday when rain showers softened the course.

Dufner matched the all-time low major round of 63 on Friday to set a course record and started with four pars in the third round before disaster struck at the par-4 fifth.

Dufner found water off the tee, chipped across the green from thick rough in a par bid, then missed a long putt coming back.

That left Dufner on seven-under with American Jim Furyk and Masters champion Adam Scott of Australia one stroke behind and American Matt Kuchar, Swedes Henrik Stenson and Jonas Blixt and American Steve Stricker two adrift.

England's Lee Westwood and American Scott Piercy were on the course at three-under.

Dufner squandered a four-shot lead with four holes to play in losing the 2011 PGA Championship at Atlanta.

US Open champion Justin Rose of England saw his title hopes take a major tumble with three bogeys and two double bogeys in the first seven holes, leaving him one-over for the tournament and reeling.

Germany's Martin Kaymer also collapsed, following a birdie at the first with back-to-back bogeys and a birdie at the seventh with three bogeys in a row to land on level par.

Blixt had the best charge among the top group with birdies at the first, fifth and ninth and no bogeys through 16 holes.

World number one Tiger Woods fired a three-over par 73, dooming his bid for a 15th major title at four-over 214 for 54 holes. He made bogeys at the first and par-3 third after finding the rough off the tee, birdied the par-3 11th but bogeys at 16 and 17 dropped him back.

Second-ranked Phil Mickelson, who won the British Open three weeks ago, struggled to a 78 - matching his worst-ever PGA Championship round - and was 74th on 10-over 220, making bogeys on three of the last four holes as well as a double bogey and triple bogey.