American J.J Henry opened up a three-point lead over Brazilian Alexandre Rocha after the third round of the Reno-Tahoe Open, being played under Modified Stableford scoring, in Nevada.
Henry, looking for his second career win on the PGA Tour, shot himself into contention for Monday morning's (NZ time) showdown with five birdies and an eagle on the par-four 14th.
The only blemish on his scorecard was a bogey at the par three 16th at the Montreux and Country Club.
Under the scoring system, at the only tournament using the method, an eagle brings five points while a birdie brings two, a bogey minus one and a double bogey or worse is minus three points.
Rocha, the overnight leader, was solid with five birdies and a bogey leaving him just a point ahead of American John Mallinger.
Argentine Andres Romero continued his good week with 10 points from his six birdies and two bogeys and at just five points behind Henry he is in with a shout for Sunday's final round.
Californian Bill Lunde, England's Gary Christian and two-times major winner John Daly are also well placed, tied for fifth, eight points off Henry.
Ireland's Padraig Harrington, a three-times major winner who has struggled for form this year, was consistent, shooting a four-under par 68 but he will need to make some eagles if he is to move up the leaderboard from 13 points back of the lead.