Cameron Smith is the only Australian in the red after his compatriots battled to stay in the hunt during a grueling second round of the US PGA Championship in Oklahoma.
Smith started in the afternoon wave trailing new clubhouse leader Justin Thomas by four shots at the windswept Southern Hills Country Club.
Seeking a second PGA Championship win, Thomas shot a straight 67 to move to six under before the afternoon starters started in treacherous conditions.
He outpointed first-round leader Rory McIlroy by one punch.
At two under par after opening with a seven-birdie 68 on Thursday, Smith hoped to make up ground when the winds picked up in Tulsa.
But his compatriot Lucas Herbert reversed course on Friday, falling to one over the championship with a three over 73.
Herbert went four before rallying with a birdie and eight pars on his nine back home.
Former champion Jason Day fought hard to get back even on the card, only to end his second-round 72 with three straight bogeys to drop to three more, nine strokes adrift of Thomas.
Marc Leishman (71) was also three up and almost certain to make it to the middle.
But Min Woo Lee, five years after a 72, and Adam Scott (70) seven more, were unlikely to earn any starting hours at the weekend.