South African Aldrich Potgieter, Australian Min Woo Lee, American Alex Smalley, Japan’s Ryo Hisatsune and Germans Stephan Jaeger and Martin Kaymer also shot 67 to share the lead on a wild day at Aronimink.
Scheffler, a four-time major winner, made five birdies against two bogeys and found himself atop the leaderboard after 18 holes for the first time in a major.
“But is it really a lead when you’re tied with six or seven guys?” the American wondered.
“The golf course was pretty challenging,” Scheffler said. “I did a good job staying in it mentally on a course that was difficult at times.”
Scheffler made birdie putts from 38 feet at seven, 28 feet at 10 and just inside nine feet at 11 to share the lead, then answered a three-putt bogey at 14 with a four-foot birdie putt at 16.
Second-ranked Masters winner Rory McIlroy was frustrated after a 74, having no problems with his blister-hit right foot but plenty with his golf swing.
McIlroy, a back-nine starter, closed with four bogeys in a row and five in his last six holes.
“I’m just not driving the ball well enough,” McIlroy said. “It has been a problem all year for the most part.
“That’s pretty frustrating, especially when I pride myself on driving the ball well.” (AFP)