Australia's Cam Davis has fallen off the pace with a disappointing second round at the PGA Championship at Quail Hollow in Charlotte, North Carolina.
Davis was two shots off the lead at 5-under-par after his first round but followed up with a 3-over 74.
He sits in a share of 27th place at 2-under through 36 holes, six strokes behind the leader, Venezuela's Jhonattan Vegas.
Davis's compatriot Adam Scott is also at 2-under, having fired an even-par 71 in the second round.
Elvis Smylie (73) made the cut at 1-over in his US major championship debut, but fellow Australians Jason Day, Cam Smith, Min Woo Lee and Karl Vilips all failed to do so.
Vegas maintained his overnight lead, despite a last-hole double-bogey.
He had been on course to enjoy a substantial halfway lead when he came to the last hole in his second round with a four-shot advantage over the field.
But that was soon halved after he made a mess of a bunker shot at 18 and then missed a putt to finish with a second-round 70, to go with his brilliant opening 7-under 64.
Vegas leads at 8-under, two shots ahead of Frenchman Matthieu Pavon (65), England's Matt Fitzpatrick (68) and South Korean Kim Si-woo (64), who managed a hole-in-one on the sixth.
"I can't really get to down on myself for making a double on 18, even though I wish I didn't make that," Vegas said.
"I just have to remember the good stuff and keep it up for two more days."
World number one Scottie Scheffler (68) was tied for fifth place on 5-under.
US Open champion Bryson DeChambeau had a 3-under 68 but capped his day with a disappointing bogey that left him five shots behind Vegas.
Masters winner Rory McIlroy (69) survived to make the cut at 1-over, as did defending champion Xander Schauffele (71).
AAP/ABC
