When he played a practice round with Adam Scott less than two weeks ago, Geoff Ogilvy was astounded how difficult the conditions were at Oakmont Country Club. They were entirely different from how the course played yesterday for the first round of the 107^th U.S. Open, even though only two players finished with sub-par scores.

"When he and I played here last Monday, 10-over would have won by five [shots]," said Ogilvy, the defending U.S. Open champion. "There are birdies out there today, whereas last Monday there weren't that many out there."

"I agree with that, because it was bone dry," said Tiger Woods, who also played a practice round that day. "The greens were a foot faster than they are right now and drier."

Phil Mickelson, who was at Oakmont Saturday, went so far as to say the greens are 3¹/₂ feet slower than they were five days ago.

Make no mistake, Oakmont is not going to play much easier than it did yesterday, when the first round of the Open championship commenced under partly cloudy skies and modest temperatures.

The fairways had a little bounce, though not the kind that usually propels balls into the rough. The greens were receptive and accommodating, more friendly than a Wal-Mart greeter, thanks to a late afternoon storm a day earlier. And the rough was not nearly as thick and long as it was on June 4, the day Ogilvy and Woods saw Oakmont as its savage best.

And, yet, despite throwing open its arms to the field of 156 players, only two players -- Nick Dougherty of England and Angel Cabrera of Argentina -- managed to better par-70. On a day when Oakmont had its guard lower than Sugar Ray Leonard, nobody was able to deliver a punishing blow and take advantage of Oakmont's hospitality.

"I definitely think that was as easy as it's going to get," said Rory Sabbatini, who shot 73.

"It's as soft and receptive as you're possibly going to have it," said Woods, who, despite the conditions, birdied just one of the final 12 holes. "And not many guys are taking it to the golf course."

None, really.

How accommodating was Oakmont?

Consider this: On the 428-yard third hole, Ogilvy whistled an approach into the middle of the green, his ball stopping about 15 feet past the pin. On a normal day, Ogilvy's shot never would have stayed on the putting surface, which slopes away from the fairway. It would have fed into the tightly cropped collection area behind the green.

But, on this day, instead of perhaps making bogey, Ogilvy was able to make birdie, one of four he posted in a round of 71.

"The rain helped a lot, especially the morning guys," Ogilvy said. "You had plenty of chances at it. If you're on the fairway, you can hit it close."

"Conditions were lovely, greens receptive and the pace good," said Ireland's Padraig Harrington, and he shot 73. "Pin positions were probably generous. Today was a good scoring day."

But, as Woods said, "Still, look at the scores."

All of which crystallizes how difficult Oakmont really can play, if the United States Golf Association would so choose. But it also foreshadows the potential for a brutal and torturous weekend for the players, many of whom thought Winged Foot in 2006 was a wrestling match.

Look out. This could be the Ultimate Fighting Championship.

"Imagine if we don't get any rain and the greens get firmer and firmer by the weekend," said Jose Maria Olazabal, one of only two players to shoot par-70. "It's going to be difficult out there."

Yeah, imagine.

Olazabal's playing partner, Sergio Garcia, shot 79. The other day, Garcia suggested par at Oakmont is 78. That being the case, he didn't have a bad round.

"Ernie looked as if he played very good golf, and he shot 3 over," Harrington said of playing partner Ernie Els, who shot 73.

J.J. Henry, a U.S. Ryder Cup player, said he "hit it as good as I ever hit it," and he shot 72.

What does that mean for weekend at Oakmont, perhaps even today?

Let's just say the air show at the Greater Pittsburgh International Airport won't be the only show with a bunch of soaring objects.