Five Australians lie in the top 10 after blistering opening rounds at the EDS Byron Nelson Championship as American Sean O&aposHair continued his recent resurgence to earn a one-shot lead. Nathan Green and John Senden fired rounds of 67 to be at three-under, two shots behind O&aposHair, who carded seven birdies at Cottonwood Valley on his way to a 65. Rod Pampling, Robert Allenby and Michael Sim are also in the hunt after day one after shooting 68s, although Allenby could have been one shot better off after missing a birdie chance on the final hole. “It&aposs hard to make birdies out there,” he said after his round. “They are just bumpy and you don&apost know if it&aposs going to go in or not.” “It&aposs frustrating, because you hit good putts and they bounce off line. It&aposs just guessing, but that&aposs the way it is. Someone&aposs going to win and you&aposve just got to put up with it.” O&aposHair, who has finished no worse than 15th in his past four starts, said he was pleased with his start to the tournament in cool and windy morning conditions. “All in all I feel pretty good with my ball-striking, and it was just a really nice round of golf,” said O&aposHair, who headed defending champion Brett Wetterich and Dane Anders Hansen by one shot. Phil Mickelson, who controversially was allowed to play despite missing the pro-am, finished poorly for a one-under 69, a score matched by Vijay Singh. “The wind was really brutal at the beginning,” O&aposHair continued. “That first hole, I nailed a drive, hit it 300-yards plus, and I still had a 5-wood in, so it was playing pretty tough out there.” O&aposHair, 24, scored his lone PGA Tour victory at the John Deere Classic nearly two years ago, shortly after firing coach Steve Dahlby, but after a mediocre season last year – 62nd on the money list – he decided to re-hire his old instructor. “Immediately, the chemistry was there, and things started clicking,” O&aposHair said of the reunion. “I&aposve been working hard for the past year-and-a-half on my backswing and it really hasn&apost been making too much sense.” EDS Byron Nelson Championship 2007 -5: Sean O&aposHair 65 -4: Brett Wetterich 66, Anders Hansen 66 -3: Nathan Green 67, John Senden 67, Scott Verplank 67, Luke Donald 67, Fredrik Jacobson 67 -2: Rod Pampling 68, Robert Allenby 68, Michael Sim 68, Jesper Parnevik 68, Bo Van Pelt 68, Ken Duke 68, Cliff Kresge 68, John Merrick 68, Pat Perez 68, Chris Stroud 68, Bob Heintz 68, Doug LaBelle II 68 Also: -1: Steve Allan 69 E: Stephen Leaney 70, Steve Elkington 70, Gavin Coles 70 +1: Jarrod Lyle 71 +2: Mathew Goggin 72, Stuart Appleby 72, Craig Perks (New Zealand) 72 +3: Nick O&aposHern 73 +4: Paul Gow 74 +5: Peter Lonard 75 +6: Mark Hensby 76