Mickelson, 29 on Wednesday, did not arrive in Pinehurst until Tuesday evening. His wife, Amy, is expecting their first baby, a girl they intend to call Amanda, in less than two weeks' time but the pregnancy has not been easy. Mickelson only decided to leave Phoenix after the couple visited Amy's doctor on Tuesday morning.
He has a bleeper on him at all times, in contravention of tournament guidelines for spectators, and will not hesitate to withdraw from the championship and return home if necessary. "There is a US Open every year but this is our first child," Mickelson said. "I don't want to miss that."
It would have been a shame to miss this US Open, too, because Mickelson's brilliant short game gives him more chance here than other venues. After 13 tour victories he is still waiting for one of the major variety. "This is an exciting time right now," he said. "It was not difficult to focus on the course, every player has to separate things in their private life. But I decided if I was going to play here, I wanted to make this week special and worthwhile, not just another made cut or top 10."
Overnight and early morning rain did not make scoring that much easier - they have machines to suck the moisture out of the greens - and the 7,175-yard was made to seem even longer. Mickelson made five birdies but Duval, his playing partner, managed something even better. The world No 1 did not have a bogey on his card.
The nearest he came to dropping a shot was at the first, following a poor drive, but he birdied the next and put together a long string of pars before having birdies at the 15th and 17th, both par-threes. "I achieved what I set out to do," Duval said. "You only need to be a little bit off on this course to be in trouble." Not troubling him at all, apparently, were the burns on his right hand caused while making a cup of coffee last week.
Montgomerie's feat of hitting every fairway was just what the Scot would expect and shows why he is a leading contender at most US Opens. However, Pinehurst No 2 is known as a "second shot golf course" and Monty failed to capitalise on being in the short grass off the tee by hitting only 12 greens in regulation. The "repulsive" greens were built by Donald Ross to reject any shot not perfectly hit.
As the bells of a nearby church chimed at eight o'clock, Montgomerie rolled in a 25-foot birdie putt on the first green for the perfect start to the day. But the next was a sign of things to come as he could not get his approach to stop on the green. His chip pulled up 10 feet short of the hole and though he sunk that for a par, bogeys followed at the next two as he went out in 37.
Bogeys at the 10th and 14th to leave him at four over but the finish could not have been better. A six-iron to 10 feet at the 17th was followed by a seven-iron to 20 feet and those putts cancelled out the memory of four three-putts, although some of those were from off the green.
Montgomerie said: "It was very important to get back into things and I am looking forward to tomorrow. I can't make the same errors again. I did the hard things well but the easy things badly. To take two sixes at the two par-fives was crazy, as was being two over after hitting every fairway.
"I have got to take advantage of my driving and while I'd like the fairways to be narrower the course is very fair. It was at its easiest today but it wasn't easy and with the rain on the front nine it was a bit miserable."
Olazabal, the Masters champion, split the fairway with his opening drive but then reverted to his wayward worst off the tee. The Welshman Philip Price, on his debut, made a solid start with a 71, despite a bogey at the last. "I snap-hooked my first three drives and was wondering how I was going to make a par," he said. But a nine-iron from the rough at the third to a foot, and the first of successive birdies, calmed the Pontypridd man.
Another first-timer, Mathias Gronberg, who is on his honeymoon after marrying his American girlfriend last week, came home in 32 to score level par. Jesper Parnevik holed his wedge shot at the 13th for an eagle in his 71 but Nick Faldo struggled to a 74.
US OPEN SCORES
Early first-round scores from Pinehurst (US unless stated)
B Mayfair, D Duval, P Mickelson
H Sutton, C Franco (Par), V Singh (Fiji), L Mize, B Watts
S McRoy, M Gronberg (Swe)
P Price (GB), J Parnevik (Swe), S Hoch, C Tidland, N Price (Zim), B Hughes (Aus)
T Tryba, T Scherrer, S Jones, P Azinger, M Slawter, C Montomerie (GB), *T McKnight, S Cink
B Chamblee, J Carter, T Lehman, R Freeman, F Couples, M Weir (Can), M A Jimenez (Sp)
D Toms, C Riley, *A Barnes, J Durant, N Begay, C Campbell, J Sluman, B Friend, F Zoeller, J Haas, N Faldo (GB)
R Goosen (SA), J M Olazabal (Sp), S Torrance (GB)
J Street, H Irwin
J Nicklaus, C Strange
J DiMarco, M Calcavecchia
M Ozaki (Japan)
* Denotes amateurReuse content