Jason Dufner (Getty Images)
American Jason Dufner was heading towards victory in the US PGA Championship in Atlanta despite several brave challenges from the European contingent.
World Number One Luke Donald, so annoyed at himself for double-bogeying the last hole of his third round and falling six behind, was only three back after playing his first 12 holes in four under.
But he went in the water on the short 15th - start of the fearsome closing stretch at the Athletic Club - and bogeyed the last as well for a 68.
World Number Two Lee Westwood also finished three under par and also bogeyed the last - his only dropped stroke of a day when he once more could not get the putts to drop.
Dufner, without a win in 147 starts on the US PGA Tour, was caught on four separate occasions by compatriot Keegan Bradley, but responded each time and birdies at the 12th and 13th took him two in front again at 11 under.
Swede Robert Karlsson was only one behind when he eagled the long 12th like Bradley, but a bogey on the 16th put him back alongside Dane Anders Hansen on seven under.
Westwood,playing his 55th Major, said: "I played lovely again today. It's just one of those things.
"I felt like I stroked it a little bit better, but, having said that, I missed twice inside six feet in the first five holes.
"When you're looking to get off to a quick start is not ideal. Then it was in the water at six and I made a nice ten footer there for par.
"I didn't really hole that much, apart from ten feet on ten.
"I have enjoyed playing great for a long time now, but unfortunately when I turn up to Majors and I don't win it's a disappointing week for everybody it seems - and obviously for me."
Donald commented: "It was a missed opportunity again. At the beginning of the day I thought if I could get to six or seven under I might have a chance.
"But the guys out front really made it tough - they are playing well - and I thought I had to press a little bit hard and take on some pins on those last few holes.
"Obviously I hit a poor shot on 15. I just didn't strike it well enough."
Dufner was suddenly four clear with four to play when Bradley went from rough into water for a triple-bogey six on the 15th and Karlsson bogeyed the 16th and 17th.
However, the leader then went in the lake himself off the 15th tee.