Phil Mickelson and Tiger Woods found themselves among the early starters in the third round of the US PGA Championship - and both needed to create history to win at Oak Hill.
The biggest comeback by a US PGA winner after 36 holes is nine shots, Bob Rosburg achieving the feat in 1959 and Bob Tway repeating it in 1986.
But Open champion Mickelson began the day 11 behind halfway leader Jason Dufner and 14-time major winner Woods was 10 off the pace after struggling over the first two days.
Mickelson at least began with good birdie chances at the first and second and made one from four feet on the third, but the world number two then three-putted the par-five fourth to drop back to two over par.
Woods, seeking a first major title since the 2008 US Open, found heavy rough from the first tee and from there hooked his second shot into a tree some 50 yards in front of him.
The world number one, fresh from shooting a second-round 61 and winning an eighth Bridgestone Invitational by seven shots on Sunday, was lucky to see the ball bounce back into the fairway, but he then played a poor pitch to 15ft and left his par putt well short of the hole.
A freshening breeze and some difficult hole locations looked set to make scoring difficult, in stark to contrast to yesterday when a rain-softened course saw Webb Simpson equal the course record with a 64 and Dufner then break it hours later with a 63.
That equalled the lowest round in major championship history and Dufner had the chance to shoot the first ever 62, but narrowly missed from 20ft on the 17th and then left a 12ft birdie attempt short on the last.
At nine under par, the 36-year-old - beaten in a play-off by Keegan Bradley in the 2011 US PGA - led by two shots from Masters champion Adam Scott and American duo Jim Furyk and Matt Kuchar.
US Open champion Justin Rose and Sweden's Henrik Stenson were leading the European challenge a shot further back, Rose after covering the front nine in 29 in his second-round 66.