Adam Scott was unable to maintain the pace of his opening round of 65 at the Safeway Open at the Silverado Golf Club in Napa in California, a second round of 73 leaving the 39-year old six shots off the pace of Bryson DeChambeau who leads by two over Nick Watney.
Scott had shared the opening round lead with Andrew Landry but, after a birdie at the first, he soon lost momentum and eventually finished one over for the day and 6 under for the tournament at the halfway stage.
Scott was not helped by poor tee shots at the 17th and 18th holes which led to a bogey and a missed birdie opportunity at the last and he now faces a big task over the weekend to reel in the leaders.
A resurgent and now injury free Cameron Percy is the next best Australian along with Aaron Baddeley, the pair just one shot behind Scott and tied for 22nd.
Marc Leishman and Rhein Gibson also made the cut but are well back.
DeChambeau is playing the event for the third occasion having finished 17th in his last visit two years ago and having missed the cut in his opening event of the new PGA Tour season in White Sulphur Springs last week this is a welcome return to form.