Alex Cejka shot a 4-under 68 to take a one-stroke lead in the Turning Stone Resort Championship.
Chris Tidland and first-round co-leader Rory Sabbatini were tied for second at 9 under after the second round at the 7,482-yard Atunyote Golf Club. Tidland posted a 69 and Sabbatini had a 70 on Friday.
Neither Cejka nor Tidland have won on the PGA Tour. Cejka has finished second twice in 227 starts since 1996 and Tidland's best performance was a tie for sixth at the 2007 AT&T Classic.
Cejka, who is from the Czech Republic, is trying to become the first foreign-born winner of this event. International players have won 11 of the last 15 PGA Tour events.
Six players were tied for fourth at 7-under 137.