Jason Day produced a stunning stretch of golf to rocket into the lead of the US PGA Championship after three rounds at Whistling Straits.
The world No.5 put together a six-under-66 to move to 15-under for the tournament, good enough for a two-stroke lead over world No.2 Jordan Spieth, but it could have been even better for the Queenslander.
Day was left to rue a double bogey at the par-four 15th and a stroke of bad luck at the par-five 16th when his second shot buried in the rough at the rear of the green, blows that really kept Spieth, who shot a seven-under 65 in the hunt.
Spieth will look to thwart Day’s attempts at a maiden major from just two shots back at 13-under.
South African Branden Grace (64) and England’s Justin Rose (68) share third at 12-under while Day’s fellow Australian Matt Jones faded late, dropping four shots in his last five holes to shoot 73 and sit tied sixth at 10-under.
Day, who started two back of Jones’s lead opened by nearly holing out for eagle on the first and tapped in for birdie instead.
He then carded bogey, birdie, bogey, birdie over the next four holes before coming alive at the turn.
Starting on the ninth he produced six straight threes on his card for four birdies and an eagle and moved up to 16-under.
Then trouble struck as he missed the 15th green left from the fairway into a bunker and failed to get the ball out on his first attempt, eventually taking double and opening the door for the challengers.
Jones opened the third round with a two-shot lead and increased it to three on the front nine only for it to close at the turn.
The Sydneysider also almost holed out for eagle on the opening hole but tapped in for birdie and then added another from 10 feet on the sixth.
Jones lashed a wild drive left into the hospitality tent on the ninth, leaving him to play from carpet amongst the fans and although his recovery shot was within half a metre of holding the green it sat down in deep rough and a bogey ensued.
Birdies at 11 and 14 had him second alone but two bogeys and a double came late on, a diabolical lie at the tough par-three 17th cruelling Jones’s hopes.
Spieth rallied late to keep his dream of a third major this season alive. The Texan played the first 10 holes one-under before birdies on six of his last eight, including three on the trot to finish.
Having already won the Masters and US Open this season, Spieth is gunning to become just the third player in history to win three of the four majors in one year, behind Ben Hogan and Tiger Woods and would likely take the top ranking if he saluted again.
Cameron Smith shot a two-under-70 to move to four under.