Nick Watney collected eight points on Friday to maintain his lead at the US PGA Tour event in Reno, three points ahead of Geoff Ogilvy.
Watney, who is seeking a sixth career win on the PGA Tour, finished two rounds at Montreux Golf and Country Club with 26 points under the Modified Stableford scoring system that rewards birdies and better and deducts points for bogeys and worse.
Players gain eight points for a double-eagle, five points for an eagle, two points for a birdie and zero points for a par.
A player loses one point for a bogey and two points for a double-bogey or worse.
Ogilvy earned seven points during his second round to sit alone in second place with 23 total points, while American Wes Roach collected 10 points on Friday to sit in third with 22 points.
New Zealand's Tim Wilkinson (5) and Tommy Gainey (10) were tied for fourth with 21 points.
Watney said the rarely used scoring system doesnt change his approach when he's on the course, and he goes into the weekend trying to keep making birdies.
"We've got a long way to go, and just try to keep my head down and stay focused on where I'm at," he said.
In 10 starts since the calendar turned to May, Watney had missed six cuts but boasted a pair of top-15 finishes including one at last week's RBC Canadian Open.
This week he has notched 14 birdies and just two bogeys in his first 36 holes.
"Well, I feel like 18 (points is) good," he said of his strong opening round. "I'm definitely proud of that round yesterday. I played great. There's some scorable holes but there's also a few really tough ones. So anything over five or six points is a good day."
Watney is seeking his first top-10 finish of the season. Currently 124th in the Fedex Cup standings, a spot in the US tour's playoffs could also be on the line for him.
The winner of the tournament also secures a place in the final major championship of the year, next week's PGA Championship at Valhalla.
Ogilvy, the 2006 US Open champion, nabbed five points with an eagle on the par-five 13th. He gave one point back with his second bogey of the day at 14, but posted his second birdie of the round at 16.
He goes into the weekend in search of his first PGA Tour title since 2010.