Conditions remained perfect all day a gentle sea breeze arriving mid morning but hardly enough to make much of a difference to what had been excellent scoring conditions all day.
It wasn't the overhead conditions that had made the Olympic Club such a test on day one but rather the demanding layout and course set-up. It was fair but tough although many of the game's great players had been humbled, perhaps none more so than world number one Luke Donald who could only manage an opening round of 79.
He summed up best the feelings of many who had been unable to come to terms with the Olympic Club. He, Lee Westwood and Rory McIlory had played together.
"Well, the top three the in the world and we make three between us. It shows how tough it is. They're aren't that many opportunities out there. Some hole locations with the firmness of the greens and the direction of the wind, the best case you're going to do is 20 feet. So it's a challenge. I tried to stay patient, tried to stay positive, but when I had those opportunities on the greens I couldn't take them."
Thompson's round of 66 was stunning but he faces a different test tomorrow as the spotlight falls on him and the papers and websites of the world carry stories on his background, his round today and his chances in the days ahead.
Joining Tiger Woods and David Toms in joint second place from the afternoon field were Nick Watney, Justin Rose and Graeme McDowell, Watney becoming part of US Open folklore with an albatross at the par five 17th.
Only six players would break par on day one, the cut score already appearing as if it will be at least seven or eight over par.
Late in the day 2010 champion Graeme McDowell birdied his final two holes of the day to creep into calculations after being somewhat off the radar.
Justin Rose did likewise although his final birdies came at the 7th and 8th holes, bearing in mind that this layout begins at the 9th hole for those playing the course the reverse way.
Of the Australians, Alistair Presnell's round of 70 on debut at the US Open was the standout. John Senden was the next best at 2 over but Rod Pampling's 74 headed the rest.
Adam Scott again disappointed at this level when he finished with a round of 76 and while not yet totally out of it is hard to imagine him producing the fightback he needs to get back into contention.
Jason Day and Aaron Baddeley had 75, former Champion Geoff Ogilvy 76, Brendan Jones 76, and Anthony Summers 76.