(Reuters) - Xander Schauffele vaulted into the halfway lead as Rory McIlroy and Tiger Woods slipped back in the second round at the BMW Championship in Pennsylvania on Friday.
Schauffele hit 17 greens in regulation and wielded a hot putter for a six-under-par 64 on the Aronimink course west of Philadelphia.
The British Open runner-up posted a 13-under 127 total, while consistent Englishman Justin Rose shot 63 to roar into second place on 11-under.
McIlroy and Woods, who shared the first round lead, could not maintain their torrid pace.
McIlroy plodded to a 69 to fall four strokes behind, while Woods (70) bogeyed the final two holes to slip five back.
Reporting by Andrew Both in Cary, North Carolina; Editing by Ken Ferris