Fathauer out in front at Mayakoba after overnight leader McDowell falters

Fathuaer, seeking his first PGA Tour win, signed a blemish-free card to go to 16 under overall, putting him one shot ahead of fellow American Jason Bohn, who is two shots clear of a four-way tie for third.

Fathuaer has never gone into a final round inside the top 10 before, and said he would endeavour not to change his approach.

"The scores that this course puts up, I don't think it matters being in the lead out here," Fathauer said. "I mean, if I had a 10-shot lead, that would be one thing, but one shot, that's an even playing field (Sunday).

"I think if I just go out and do what I came here to do, I'd like to see where it puts me at the end of the day because if I just stick to my plan, I'll be happy no matter what happens."

Bohn went round in 65, making an eagle on the par-five 13th but then dropping a shot on the 18th that cost him a share of the lead.

Still, it was enough to keep him clear of Justin Leonard, Russell Knox, Harold Varner III and former US Open champion Graeme McDowell, who sit at 13 under.

McDowell held the overnight lead but instantly hit trouble with a double bogey on the first and a bogey at the second. He rebounded with birdies on the fifth, sixth, 10th and 11th but dropped another shot on the 13th before a birdie on the 17th.