Course record puts Bradley in USPGA lead Australia's Mark Leishman fired five first-round birdies at the US PGA Tour's Byron Nelson Championship, but remains six shots off the pace thanks to a sizzling start by American Keegan Bradley. Bradley managed 10 birdies and an eagle in a course-record 60 to seize a three-shot lead on Thursday. The stunning 10-under par round came despite two bogeys at the TPC Four Seasons Resort, where he took advantage of a rain-softened course to set an early target that no-one could match. South African Charl Schwartzel had seven birdies and no bogeys in his seven-under 63, which gave him sole possession of second place. Leishman was the best-placed Australian in a tie for ninth after carding a four-under 66. Countrymen Nathan Green and Scott Gardiner were one shot behind, while Cameron Percy (68), Stuart Appleby (69), Greg Chalmers (69), John Senden (71) and Jason Day (72) were further back in the field. "I birdied more holes than I didn't, which is rare," Bradley said. It was just an explosive type of round. The former PGA Championship winner said playing partners Jason Dufner and Matt Kuchar kept the round relaxed. "Just a really fun round," Bradley said. It kind of felt like a Saturday morning round with my buddies. The 60 ties the tournament record for a low round held by Sam Snead and Arron Oberholser, who shot their 60s on different courses. Bradley, the 2011 Byron Nelson Championship winner, had five birdies in his first seven holes. After back-to-back bogeys at 18 and one, he played his last seven holes in eight-under par, including an eagle at the par-five seventh. Schwartzel, playing the tournament for the first time, also benefited from a morning tee time. "You couldn't ask for much better," he said of the conditions. Seems like you don't get many of those opportunities, so being out here first was a bit of an advantage. Schwartzel matched his low round on the US PGA Tour. Chinese prodigy Guan Tianlang, trying to make his third cut in as many starts on the US PGA Tour, carded an even-par 70 that included two birdies and two bogeys. The 14-year-old, who earned low amateur honours at the Masters as the youngest player ever to tee it up at the year's first major championship, was tied for 77th.