McIlroy became only the fifth person in history to reach double digits in a US Open and the fastest to do so. It took him only 26 holes to achieve that feat, his holed approach at the 8th hole setting that milestone.
Rory McIlroy is the first player in history to reach 13 under at the U.S. Open. It breaks the previous record for most strokes under par at any point (previously 12 under, shared by Gil Morgan in 1992 and Tiger Woods in 2000).
The 22 year old Northern Irishman leads by six shots over Y.E. Yang but it was not only the margin but the ridiculous ease and emphatic nature of the display that left most reeling with the quality of what they had seen.
Not only is McIlory's lead by six over Yang but there are a further three shots back to the large group in a share of third position at 2 under, further emphasising just what he has achieved to date.
McIlroy played early on day two and turned what had already been a very good start into something even more special with an eagle from 113 yards at the 8th when he spun his approach back form the back of the green into the hole.
There were clearly many more great shots but the one I enjoyed as much as any was the 4 iron second to 12 feet at the par five 16th to set up a second eagle of the day. The putt missed but the quality of that approach told the story.
McIlroy was threatening to end the contest almost before it had begun with the birdie there and again at the 17th but at the 18th his tee shot found the rough. Even from the fairway at the last the approach to the back flag position at the outstanding final hole at Congressional is a scary proposition. McIlroy was clearly thinking of sticking with his policy of continuing to attack and hit a good shot but pulled it more than he had intended. It caught the camber and fed down into the water.
The resultant double bogey was disappointing for him but perhaps not for the rest of the field as they need some level of encouragement if this event has any chance of remaining a contest over the closing 36 holes. In dropping two shots he gave at least some hope to his chasers despite the fact they are only seeing his dust at the moment.
One of the first questions asked was of the double bogey. "I mean the lie was decent. I was just trying to play out to the front right portion of the green. And I just got a little bit of grass caught in between the club face and the ball. The club turned over a bit and that's really that was all that happened. I really wanted to make that up and down just so I could only drop one shot. Because there are such things as good bogeys in a U.S. Open. That would have been one of them."
The almost predictable next question was on his demise at Augusta National. What has he added to his game since then? "I said a couple of things that I've done is just a little change to my attitude and my demeanour, maybe, on the course. I did a piece after Augusta where I said I needed to be a little more cocky, a little more arrogant on the golf course, and think a little bit more about myself, which I've tried to incorporate a little bit, just on the golf course.
"I just try and have a bit of an attitude, you know? But that's really been when I get myself in these positions, I have to really make sure that I'm that I don't get ahead of myself and I don't start playing defensively. I have to still play aggressively to the targets that I pick. And that's really the main thing, even if you get 4 or 5 ahead of the field, 6 ahead of the field or whatever, you're trying to get 7 ahead, 8 ahead, ten ahead, whatever, you're just trying to keep going."
There is little doubt that there is pressure on McIlroy over the final two rounds. Not only because he now has a breakthrough major in his sights but that there are a couple of collapses in his background.
McIlroy has not achieved what he has over the opening two rounds however without the physical game to win an event like this. The question will be the mind game but it is important to remember similar questions of other golfers about their capacity to get the job done have been asked in the past before the breakthrough. Tom Watson comes to mind and he would eventually go on to win eight majors. It is also important to note that McIlroy is still on a huge learning curve.
Y.E. Yang has slipped under the radar here. Even in his initial press conference immediately after he had completed his round late in the day there were few media present. The Korean has however a proven major record having stared down and beaten Tiger Woods in the final few holes of the US PGA Championship in 2009.
Like so many of the Korean golfers, male or female, they enjoy strong constitutions and if he was to apply pressure to McIlroy over the closing 36 holes then it would not be the surprise his victory two years ago was.
The group at 2 under and sharing third includes the ever present Matt Kuchar who birdied three of his last four holes to give himself an outside chance at the weekend. Others in that group are Zach Johnson, Robert Garrigus, Brandt Snedeker and Sergio Garcia.
The game's leading players fought back today after horror starts to the tournament. Luke Donald, Lee Westwood, Martin Kaymer, Steve Stricker and Phil Mickelson all shot under par rounds and while they may be all a long way from McIlroy right now they are within striking distance of Yang and any slip by the leader will assist their current outside chances of winning the title.
The leading Australians are John Senden and Marc Leishman at even par and in a share of 15th position. Jason Day is at 1 over but the only other Australian with a chance to make the weekend is Nick O'Hern but when he returns to the course at 8.15am on Saturday morning to complete his round will face a six footer for birdie at the last to force his way into the weekend field.
Adam Scott found the water at his last hole to miss by one and Scott Hend's fairytale came to an end with a second round of 78 to also miss by just one.