Washington - Jason Dufner holed out from the fairway for an eagle en route to a second straight 65 that gave him a five-shot lead with a record-setting 36-hole total at the Memorial on Friday.
Dufner's 14-under par total of 130 put him five shots in front of fellow American Daniel Summerhays, who carded a 69 for 135.
Rickie Fowler was alone in third after a 66 for 136.
"Did everything pretty well," said Dufner, whose halfway total was one stroke better than the previous 36 hole record set by Scott Hoch at Muirfield Village in Dublin, Ohio, in 1987 and matched by Fowler in 2010.
"I made some nice pars and rolled in some putts," he added, although the highlight of his day didn't involve putting.
He fired his second shot at the par-four 18th, his ninth hole of the day, from 175 yards out in the center of the fairway. It landed past the pin and spun back into the hole for an eagle.
He added five birdies to cement his lead.
"We've got two more rounds to go," said Dufner, the 2013 PGA Championship winner. "We'll see how the course changes, if the wind picks up, gets running fast, it plays different. If we get some showers like they're talking about it will be soft and be a little bit more scoreable ... you keep trying to shoot as low as you can."
Summerhays, seeking a first US PGA Tour victory, had six birdies and three bogeys in his 69.
Fowler, who started the day tied for 13th on two-under, teed off on 10 and climbed up the leaderboard with a six-under effort. Four of his six birdies came on his inward run, including three in a row at the sixth, seventh and eighth.
"Definitely pleased," said Fowler, whose opening round had included a triple-bogey. "I was able to get rid of some mistakes I made yesterday."
Former world number one Jordan Spieth had three birdies and three bogeys in an even par 72 that left him tied for fourth on six-under 138. He was joined by Jamie Lovemark (69) and Justin Thomas (71).
Sweden's David Lingmerth, the overnight co-leader with Dufner, followed up his opening 65 with a two-over 74 and was in a group of six players on 139 that also included Scotland's Martin Laird, Argentina's Emiliano Grillo and two-time Masters champion Bubba Watson.
World number one Dustin Johnson, two weeks away from his US Open title defense at Erin Hills in Wisconsin, missed the cut, following up his opening 78 with a two-over 74.
Spain's Jon Rahm also failed to make the cut, which came at three-over par. He had five bogeys in his five-over 77 including four in a row to end his round.
Former world number one Jason Day rebounded from an opening 75 to card a 71 that saw him make it to the weekend with a stroke to spare.
Leading second-round scores on Friday in the PGA Tour's Memorial tournament in Dublin, Ohio (USA unless noted, par-72):
130 - Jason Dufner 65-65
135 - Daniel Summerhays 66-69
136 - Rickie Fowler 70-66
138 - Jamie Lovemark 69-69, Jordan Spieth 66-72, Justin Thomas 67-71
- Martin Laird -71-68, Matt Kuchar 69-70, Emiliano Grillo (ARG) 71-68,
David Lingmerth (SWE) 65-74, Bubba Watson 71-68, Kevin Kisner 70-69
- Graham DeLaet (CAN) 73-67, Lucas Glover 67-73, Shane Lowry (IRL)
72-68, An Byeong-Hun (KOR) 68-72, Jason Kokrak 73-67, Marc Leishman
(AUS) 70-70, Phil Mickelson 70-70
141 - Kyle Stanley 74-67, Russell Knox (SCO) 71-70, Charl Schwartzel (RSA) 70-71, Brett Coletta 72-69
- Kevin Streelman 73-69, Padraig Harrington (IRL) 71-71, Brooks Koepka
69-73, Bill Haas 73-69, Adam Scott (AUS) 76-66, Bud Cauley 75-67, Sam
Saunders 68-74, Ross Fisher (ENG) 73-69, Camilo Villegas (COL) 74-68,
Steve Stricker 74-68, Pat Perez 70-72