Bernd Wiesberger of Austria shot a second straight 7-under 65 Saturday to open up a five-shot lead after the third round of the Ballantine's Championship.
He equaled the Blackstone Golf Club course record he had set the previous day to reach 14-under 202.
Marcus Fraser of Australia was in second after a third-round 69, with England's Oliver Fisher (67) and Chile's Felipe Aguilar (68) one shot back in a tie for third.
The 26-year-old Wiesberger led by one shot after the second round and he extended his advantage with a 15-foot birdie putt on the fourth green and another from five foot at the sixth.
He made five more birdies on the back nine to close in on his first European Tour victory.
"I have never had a five-shot lead in a European Tour event," said Wiesberger, who lost a playoff to Thomas Bjorn at the 2011 Johnnie Walker Championship at Gleneagles in Scotland. "But I am not thinking about trying to win by one shot, I am thinking maybe to win by 10 shots. I am going to try to relax and stay positive."
Fraser has won twice on tour including victory at the Ballantine's in 2010 at Jeju Island, but he conceded his young playing partner would be difficult to beat.
"He played great today," Fraser said. "He gave himself a chance of birdie on almost every hole and he putted great. If I was a betting man I would put my house on him winning."
Two of Europe's veteran Ryder Cup stars — Ireland's Paul McGinley and Spain's Miguel Angel Jimenez — climbed up to tie for fifth at 7-under 209.
The 45-year-old McGinley is playing only his fifth tournament since undergoing his seventh knee operation last December. Having missed two cuts and withdrawn from the Trophee Hassan II in Morocco because of fitness problems, McGinley had expressed doubts about his playing future. But after a flying start which saw him make five birdies in his first six holes, he finished with a 65.
Jimenez had a 69 and joined McGinley seven shots off the lead.