American journeyman Jason Dufner held a one-shot lead after parring the first three holes in the PGA Championship final round Sunday as his closest challengers all faltered. Dufner, who tied for fifth in last year's PGA Championship at Whistling Straits, looked very relaxed with regulation golf to remain at seven under par in dazzling sunshine at Atlanta Athletic Club. PGA Tour rookie Brendan Steele, joint pacesetter with Dufner overnight, bogeyed the opening hole after finding bunkers off the tee and also with his approach to slip back to six under. Fellow rookie Keegan Bradley, a stroke off the lead overnight, briefly joined Dufner at the top when he rolled in a 20-footer to birdie the par-four first. However, the 25-year-old American bogeyed the par-four second after finding trees to the left off the tee to slip back alongside Steele and veteran Scott Verplank, who had birdied the second. Swede Robert Karlsson, two under for the round, was a further stroke back in a tie for fifth with Dane Anders Hansen, who had completed four holes. American players are bidding to end an unprecedented run of six majors without a champion but Britons Like Donald and Lee Westwood both made significant moves in the final round. World No. 1 Donald birdied two of the first six holes to get to three under, four off the pace, level with second-ranked Westwood who had eight holes to play. Reigning Masters champion Charl Schwartzel of South Africa and American David Toms, whose lone major came at the 2001 PGA on the same course, were the only major winners in the final nine groups. The 7,467-yard course offers up a fearsome final foursome of holes where the title figures to be won or lost. Australian Robert Allenby made five birdies in nine holes to stand five-under for the day and two-under for the event but bogeys at 15 and 17 dropped him back. Spain's Sergio Garcia and four-time major winner Phil Mickelson, who began at level par, each played the front nine Sunday in two-under while Spain's Pablo Larrazabal birded three holes in a row in firing a four-under 66. The biggest last-round comeback for victory in PGA Championship history was the seven-stroke rally by John Mahaffey in 1978, which left the door open for plenty of players. World No. 1 Luke Donald and World No. 2 Lee Westwood lurked within reach, the Englishmen each seeking their first major crown. Donald was on two-under, five strokes back, with Westwood on one-under. Australian Adam Scott was also at two-under. US Open champion Rory McIlroy fired his second consecutive 74. McIlroy finished on 11-over 291. He will rest for two weeks until his next event, the European Masters in Switzerland in September.