Returning to the scene of his first US PGA Tour victory, Jason Day has battled strong, gusty afternoon winds to be well-placed after the opening round of the Byron Nelson tournament.
Day posted a two-under 68 despite four bogeys and joined fellow Australians Marc Leishman and Greg Chalmers in a tie for 14th, four shots behind American joint leaders James Hahn and Ricky Barnes.
Struggling to regain form that made him world No.1 last year, No.4 Day is back at the TPC Four seasons course in Texas where he became the youngest Australian winner on the tour in 2010, having missed the event the last four years.
He had the misfortune of having his ball roll off the green after hitting the stick with his approach shot when forced to settle for par at the par-5 16th but finished in style with made a long birdie putt at 18.
Hahn rolled in a 20-footer to birdie the 18th for his share of the lead, while fellow early starter Barnes rode to the top of the leaderboard on the strength of five birdies on the front side.
Tied for second on four-under-par 66 are Americans Matt Kuchar, Jason Kokrak and Cameron Tringale, along with Venezuelan Jhonattan Vegas.
American world No.1 Dustin Johnson battled through the afternoon winds to post a 67 that required just 24 putts as he chases a fourth win in six outings.
Rod Pampling is best of the other Australians at one-under, while Brett Drewitt (two over), Cameron Percy), Geoff Ogilvy and Matt Jones (all three over) , Stuart Appleby (six over), Steve Bowditch (10 over) all have ground to survive the cut.
Bowditch's ugly round featured two triple bogeys, one double bogey and four bogeys.
Defending champion and Masters winner Sergio Garcia bogeyed the last to finish with a three-over 73.