Casey Wittenberg fired an 8-under 63 on Thursday to grab a 2-stroke lead after the opening round of the Wichita Open.
Wittenberg, a former U.S. Amateur runner-up, earned his first tour win earlier this year at the Louisiana Open.
Kevin Johnson, the 2006 champion, and Jason Gore, the Nationwide Tour leader in career wins, share second place at 6-under 65.
Fabian Gomez, the 2007 runner-up, carded a 5-under 66 and is one of 11 players tied for fourth on the North Course at Crestview Country Club.
Wittenberg, who tied for 10th at the U.S. Open last week, started his round on the back nine and opened with a pair of pars. He got on the board with birdies at 12 and 14.
The 27-year-old drained a 15-footer for eagle at the par-five 18th to make the turn at minus-4.
Wittenberg ran off three consecutive birdies from the third to move atop the leaderboard at 7-under. At the ninth, his last, Wittenberg rolled in a 25-foot birdie effort to close out his round.
"This course is a different beast. You've got to go out and make birdies here, especially on a day like this," Wittenberg said. "Last week, if you made three or four birdies at the U.S. Open, you played a pretty good round of golf. It was an adjustment, but I've done this long enough to know that if I want to have a good week here, I've got to go out and make some birdies."
Johnson also started on the back nine. He birdied the 11th, then eagled the par-five 14th. Johnson made the turn at 5-under after birdies on the 16th and 18th.
The six-time Nationwide Tour winner birdied the first to get to 6-under, but he parred his final eight holes.
Gore, who has seven tour wins, played right behind Johnson and matched all of his back nine scoring. Gore birdied 11, 16 and 18 to go along with an eagle on the 14th.
Around the turn, Gore birdied the par-five second, but gave that stroke back when he bogeyed the seventh. Gore birdied the ninth to share second with Johnson.
Gomez shares fourth place with Mathias Gronberg, Charles Warren, Scott Gardiner, Steve LeBrun, Justin Hicks, Peter Tomasulo, Andrew Svoboda, Andres Gonzales, Matt Harmon and Jim Herman.
NOTES: Wittenberg set the scoring record in his win at the Louisiana Open, when he posted 260 over four rounds... Justin Bolli holed his second shot at the par-5 14th for the third double-eagle of the year on the Nationwide Tour...The start of the round was delayed one hour after 1 1/2 inches of rain fell overnight, which forced officials to put lift, clean and place rules into play for the opening round.