Top-ranked Scheffler seizes three-stroke lead at PGA Memorial
The two-time Masters champion, seeking his fifth victory of the year, stood on nine-under 135 after 36 holes at the Jack Nicklaus-hosted event in Muirfield Village.
"You've got to play it fairly conservative out here, just with how much trouble there is around the golf course. There's a lot of hazards and you've got the heavy rough," Scheffler said.
"Can be really tough to judge the wind. I'm just trying to do my best to execute. Sometimes I get the wind right and hit the right shot. Other times, things don't work out as well.
"We'll see how the winds are this weekend. I think it'll only get tougher."
Defending champion Viktor Hovland of Norway fired his second 69 to share second with Canada's Adam Hadwin, the 18-hole leader who settled for a 72 to finish on 128.
"Some nice gusts there," Hovland said. "And some steady winds makes it even more difficult. So did a good job of just hitting a bunch of fairways, but even then, there's a lot of thinking and guessing going into the greens.
"It's just hard to get it close to the hole, but I managed to do that somehow."
South African Christiaan Bezuidenhout and American Keegan Bradley shared fourth on 139 with Sweden's Ludvig Aberg on 140.
Four-time major winner Rory McIlroy was on 141 with Americans Tony Finau, Akshay Bhatia and second-ranked Xander Schauffele.
Scheffler has four triumphs and two runner-up efforts in his past seven starts and appeared poised for another top-two finish in the final tuneup for next week's US Open.
The 27-year-old American seeks his 10th career PGA Tour title.
Scheffler dropped his approach to eight feet and sank the birdie putt at the third hole to match Hadwin for the lead, then moved ahead with a birdie putt from just inside eight feet at the par-5 fifth to reach 7-under.
Scheffler made another birdie putt from just inside six feet at the ninth to reach the turn ahead by two.
At 10, Scheffler missed the green with his approach but sank a putt from just beyond 15 feet to save par. At the par-5 11th, he found the left rough and a greenside bunker then missed a par putt from just inside 10 feet.
Scheffler found the left rough off the 13th tee and missed an 11-foot par putt, dropping him back into a share of the lead with Hadwin.
"That's a bad miss there," Scheffler said. "Unfortunate series of events but still felt like I was hitting it really well."
Scheffler righted his round, however, at the par-5 15th, when he reached the green in two and sank an eagle putt from just inside nine feet to restore his two-stroke edge.
"It was nice to get one in close on 15 and make a putt," Scheffler said.
At 18, Scheffler sent his tee shot into a fairway bunker, landed his approach just inside 12 feet, then curled in a birdie putt.
"Got a good break," Scheffler said. "Ended up in the bunker instead of the rough and was able to get up there on the green and hole another nice putt."
Hardest round ever
Hovland birdied three of the last six holes, a tap-in at the last matching him with Hadwin, who took a double bogey at 17 after finding the fairway and greenside bunkers.
Schauffele, coming of his first major win at the PGA Championship last month, shot 73 but hit his most spectacular shot at 14. He soared way right of the cart path, then over the green into a bunker, but blasted in for birdie from 28 feet.
Jackson Koivun, a 19-year-old US collegian, became the first amateur since 2009 to make the Memorial cut, doing so on the number at 148 despite a 76.
"It's awesome," Koivun said. "Today is probably the hardest golf conditions and course I ever played."