Lee Westwood picked up where he left off on Saturday, but Rory McIlroy responded with an opening birdie of his own and led the US Open Championship at Congressional Country Club by an incredible nine shots.
After a third round 65 that was the lowest round of his Major career Westwood pitched to four feet to move alongside Korean Y E Yang in second place at six under par.
But in the group behind McIlroy, despite driving into the edge of a divot, hit his approach to nine feet and made no mistake to go to 15 under.
It kept the 22 year old firmly on course to become the youngest winner of the title since Bobby Jones in 1923, the second successive Northern Irish champion and Europe's second youngest Major champion after Young Tom Morris nearly 140 years ago.
Two months after his closing 80 from four ahead at The Masters Tournament McIlroy had set 36 and 54-hole scoring records already and needed only a one over par 72 to establish a new tournament mark, while the record under par mark for the tournament was the 12 under of Tiger Woods at Pebble Beach in 2000.
Luke Donald double bogeyed the 18th - for the third time in the week - but a 69 lifted him to five over and meant Westwood almost certainly needed to finish second to take back the World Number One spot he lost to Donald in a play-off at Wentworth three weeks ago.
McIlroy had not three-putted all week - and he kept it that way after leaving his 45 foot birdie attempt on the short second seven feet short.
Westwood had missed a 15 foot chance on the same green and did the same at the 466 yard third, while Yang's two pars kept the gap - the chasm more like - at nine.
The crowd who had taken the youngster to their hearts did not have long to wait to see him ten in front and 16 under par - four more than Woods' mark 11 years ago, although he won by a Major record 15 at Pebble Beach.
It came with another towering iron that spun back to within four feet of the flag on the 470 yard fourth.
A three-putt bogey was an even bigger possibility at the fifth when McIlroy, having driven into sand, left a 70 foot putt 14 feet short, but in it went for par.
The job had still to be completed, of course, but after his round Donald said of McIlroy, still ten clear: "I think he has probably the most talent I've ever seen from a golfer.
"I really hope he goes out and extends his lead and see if he can get to 20 under."
Swede Fredrik Jacobson, meanwhile, made it a three-way tie for second when he birdied the long sixth.
