Jason Dufner makes history with 63 to grab PGA Championship lead after Round 2

American Jason Dufner matched the low 18-hole score in major golf history on Friday, firing a seven-under par 63 to seize the lead after two rounds of the PGA Championship.

On an Oak Hill course that was drenched by rain showers all morning, Dufner fired five birdies and an eagle to finish on nine-under 131 after 36 holes for a two-stroke lead in the $8 million tournament.

"The rain, the soft golf course, made it scorable," Dufner said. "But to join history, to shoot a 63 in a major, pretty unbelievable. To be leading the tournament, even better. Hopefully it will propel me to a great weekend."

Masters winner Adam Scott of Australia and Americans Jim Furyk and Matt Kuchar shared second on 133, with Sweden's Henrik Stenson and England's Justin Rose, the US Open champion, on 134.

Dufner became the 24th player to shoot 63 in a major. The feat has been done 26 total times, with Australian Greg Norman and Fiji's Vijay Singh accomplishing it twice.

Jack Nicklaus, Tiger Woods, Rory McIlroy, Nick Price and Nick Faldo are among the other players to shoot 63 in a major.

"That's pretty good company right there," Dufner said.

Dufner set a course record at Oak Hill, breaking the mark of 64 shared by countrymen Ben Hogan from the 1942 Times-Union Open, Curtis Strange from the 1980 US Open and Webb Simpson earlier on Friday.

Dufner had a 12-foot birdie putt at the 18th hole to shoot the first 62 in a major but left it 18 inches short and his tap-in for par dropped in off the right edge of the cup.

"You don't want to leave anything short to make history," Dufner said. "But I was able to two-putt and at least share history."

Dufner holed his approach shot for an eagle at the par-4 second and followed with back-to-back birdies at the par-5 fourth and par-4 fifth.

On the back nine, Dufner birdied the par-3 11th and par-5 13th, then birdied the par-4 16th. He missed a 15-foot birdie putt at the 17th, setting up the drama at 18.

Dufner won his first US PGA title after 163 tries last year at New Orleans, then followed by taking the Byron Nelson Championship.

Dufner shared fourth at the US Open in June and lost the 2011 PGA Championship in heartbreaking fashion.

Owning a four-stroke lead on the field with four holes to play at Atlanta Athletic Club, Dufner led eventual winner Keegan Bradley by five strokes, but Dufner made bogeys at 15, 16 and 17 while Bradley birdied 16 and 17 to set up a three-hole aggregate playoff that Bradley won by a shot.

Kuchar made five birdies but closed with a bogey.

"This was definitely the good side of the draw," Kuchar said. "People took advantage of the conditions to make some birdies."

World number one Woods fired a 70 to stand on 141 for 36 holes, 10 off Dufner's pace. He made four birdies and four bogeys, going birdie-bogey-birdie bogey over the last four holes.

"I'm so far back that if the leaders go ahead and run off with it and shoot a low one tomorrow, I'm going to be pretty far behind," Woods said.

Scott reached eight-under three times but in each instance made bogey at the next hole to fall back.

"If I was really hot with the putter, I really could have made it something to cherish," Scott said. "I should have made some of those putts the way the greens were rolling."

Rose opened bogey-bogey and followed a birdie at the 14th with a bogey at 18, but then the rain stopped and Rose ran off three birdies in a row, added another at the fifth and closed birdie-birdie to stay in the hunt.

"I was trying to hang on and stay alive out there," Rose said. "Water was coming down so hard it was in my face. At the turn the rain stopped and I could get back and really start playing my game."

Simpson flirted with a 62 as well. He began on the back nine with back-to-back birdies, added another at the 14th and ran off four birdies in five holes in a streak that ended at the par-3 sixth, but a bogey at the seventh left him only with a share of the course record for a few hours.

British Open winner Phil Mickelson fired his second 71, lamenting his inability to take advantage of the rain.

"With the greens so soft, you can attack the course," he said. "Unfortunately my game wasn't sharp enough to attack."

Defending champion Rory McIlroy, enduring a season of struggles, started on the back nine and birdied four of his last seven holes for a 71 and a total of 140.

"That's two front nines I've played pretty good this week," McIlroy said. "If I get the back nine sorted out I'll be doing fine."

In all 75 players from the field of 156 made the cut on 143. Among those not playing on the weekend are former Masters champion Bubba Watson, South Africa's Ernie Els and England's Luke Donald.