Brooks Koepka will take a record seven shot lead into the final round of the US PGA Championship after a level par 70 on day three at Bathpage State Park BK Course.
The defending champion had been utterly dominant over rounds one and two, as he sent records tumbling over the notoriously tough Long Island layout.
He entered Saturday with a seven shot lead at 12 under and stayed there after 54 holes as tougher conditions in round three saw the course truly bare its teeth.
The American extended his lead to eight shots at one point and then saw it cut to five, before establishing the largest 54 hole advantage in US PGA Championship history over Thai Jazz Janewattananond, World Number One Dustin Johnson and his fellow Americans Luke List and Harold Varner III.
Janewattananond and Varner shared the lowest rounds of the day with a pair of 67s, while Johnson and List both carded rounds of 69.
A victory for Koepka would see him become the first player in history to win both the US PGA Championship and U.S. Open back to back, in the process becoming the first player to hold two Major titles back to back simultaneously.
And should he win a fourth Major out of his last eight on Sunday, he will become just the fourth man to win so many in so short a span alongside Ben Hogan, Jack Nicklaus and Tiger Woods.
A victory would also make the 29-year-old - who won three European Challenge Tour events in a seven week period in 2013 to graduate onto the European Tour - the first wire to wire winner of a Major since Jordan Spieth at The 2017 Open Championship.
Asked if he had any doubt whether he would win, Koepka said: "No. I feel confident. I feel good. I feel excited.
"I'm just playing to play good golf and wherever that puts me, I'll be satisfied if I just go and play one more good round.
I feel confident. I feel good. I feel excited - Brooks Koepka
"If you start treating tomorrow's round differently than every other round, I feel like that's where I would maybe be nervous or start worrying about this, worrying about that. It's just like any other round I've ever played. It's 18 holes. Try to hit the fairway, try to hit the green and try to make birdie."
Koepka hit a wonderful approach into the second to stretch his lead to eight shots and while Johnson birdied the third and fourth to cut it back to seven, the leader put an approach to three feet on the fifth.
An excellent approach from Johnson into the ninth cut the lead again but when he bogeyed the tenth and 11th, Janewattananond was on his own in second.
The 23-year-old hit a tee shot to seven feet on the third, took advantage of the par five next and then hit a nice approach into the sixth before holing from 13 feet on the tenth.
Koepka had done well to save par on the seventh and eighth but bogeyed the ninth and tenth, with Janewattananond dropping a shot on the 14th.
List added to a holed bunker shot on the sixth with a chip-in on the 12th, and when he made a long putt on the 13th and a 13 footer on the next, Koepka's advantage was down to five.
Koepka hacked his way down the par five 13th but made a slippery right to lefter for birdie and Johnson was once again his nearest challenger as List finished bogey-bogey.
Johnson sandwiched a bogey on the 14th with birdies on the 12th and 15th as Koepka three putted the 16th, but the 34-year-old bogeyed the last.
Varner III - the 2017 Australian PGA Championship winner - had set the target with birdies on the fourth, 13th and 18th and Janewattananond soon joined him at five under as he recovered from a bogey on the 17th with a birdie on the last.
England's Matt Wallace carded a level par 70 to sit alongside Japan's Hideki Matsuyama at four under, a shot clear of Patrick Cantlay, Xander Schauffele, Adam Scott and Spieth.