The headlines in the papers will rightly proclaim the brilliance of Rory McIlroy, but his was just one of three genuinely unbelievable rounds of golf played at Congressional on Thursday.
And we mean unbelievable. Bunker Mentality was genuinely pinching itself at times to confirm what was being witnessed.
First up, McIlroy. His 65 was a Major marvel, one of those effortless demonstrations of golf at the highest level that leaves everyone watching it amazed that he didn't finish several shots better.
His drives were long - often ludicrously long, as on the par-5 sixth where he left himself a waft with a mid-iron shot to the green - but it was his iron play that truly impressed. Time and again he almost knocked the pins out with his approaches, and ruthless putting saw him finish off pretty much of all of his truly makeable opportunities.
Only in his short game did he fail to shine, though more through lack of opportunity: he had just one bunker shot to hit - a poor one, which he made up for with a 20-footer into the centre of the cup.
The Northern Irishman now finds himself at the top of the leaderboard after the opening day for the third time in the last four Majors.
The question now is whether he can go on from here and win. At last year's Open Championship in St Andrews he blew up on day two with a round of 80; at the Masters in April he hung on until Sunday, when he blew up with an 80. Let's hope that he can hang on until Monday this time, and save his 80 for his first practice round at his next tournament.
As amazing as McIlroy's round was, Phil Mickelson's 74 was no less compelling, despite being nine shots worse, mainly because it should have been more like 29 shots worse.
The world number four and five-times US Open runner-up started the day by putting his opening tee shot into the water.
It went downhill from there.
Time and again he took a 2-iron off the tee for safety and still ended up in trouble. He hit a driver out of the rough from thick trees, managed to drive into bunkers 50 or 60 yards off line and on entirely different holes, ended up in waist-high rough, blindsided himself on greens more than once, gave himself near impossible recovery shots from thick, wet rough, and failed to make his birdie chances even on the rare occasions that they did present themselves.
The left-hander made a good show of wincing when his 30ft birdie putt on the final hole missed by an inch, but the truth is that he will take his 74 and run away quickly without stopping to wonder how he isn't already out of the tournament.
We're not exaggerating. Mickelson was genuinely abysmal, so much so that it was as if the ghost of Maurice Flitcroft had possessed him.
Yet at the same time he also seemed possessed by the ghost of Seve Ballesteros, stringing appalling drives together with wild slashes out of the rough and ludicrous lob shots in such a way as to shoot just three over par on a brutally tough 7,500+ yard golf course.
At one point spectators were warned that they might consider leaving the course due to a risk of lightning in the area. Almost all stayed, for the simple fact that they had probably braved far worse danger simply by being in Mickelson's vicinity when he was using any club except a putter.
The third amazing round of the day, however, might just be the most extraordinary of the lot: that of Robert Rock.
The English journeyman teed up on Thursday after spending several days (and £15,000) with lawyers trying to get a last-minute US visa. Having succeeded late on Wednesday he managed to fly to New York, landing at 11.30pm. He jumped in a taxi at JFK Airport and asked to go to Washington DC, to the delight of the cabbie who charged him $1,000 for the ride.
He eventually got to the course at 3.30am on Thursday morning, teed up less than 12 hours later without any chance even to walk the course, and shot a round of 70 on his US Open debut.
Obviously it's a lot less painful spending £20,000 on getting to a tournament for a guy who just won 250,000 euros by winning the Italian Open, but Rock's persistence and talent in the face of what must be total exhaustion is utterly inspiring.
Let's just hope that when the adrenaline wears off on Friday he still has enough in the tank to make the cut - and give himself a chance of at the very least breaking even.
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Three years ago, when Tiger Woods skipped The Open at Royal Birkdale due to his knee surgery, people talked openly about it being the "asterisk Open", on the basis that the world's greatest player was not in attendance and therefore the winner's achievement would be diminished.
That suggestion was rendered ludicrous by Padraig Harrington's finish that year, one of the great final rounds ever seen at a Major.
This time round, in the absence of 14-times Major winner Woods, we didn't even have to wait until Sunday to completely forget what we were missing.
And we can't help but think that when the world stops missing Tiger, maybe it really is the beginning of the end for a golfing great.