Roberto Diaz shot a flawless 62 on Thursday to take the first-round lead at the John Deere Classic.
Scotland's Martin Laird is another shot further back in a tie for fourth.
"I just feel that everything clicked," Diaz said in quotes on the PGA Tour's website.
"I've been playing pretty solid throughout the year. The driver has been awesome. I've been hitting a lot of fairways, and today I hit good numbers all day, and that helps."
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