PINEHURST, N.C. (AP) -- Dustin Johnson had a pair of 69s to start his U.S. Open, scores that are good enough to be in the lead or not too far from it at Pinehurst No. 2.
''I would have taken it on Wednesday,'' Johnson said, pausing before answering the second part of the second.
''And no, I wouldn't have thought it would be eight shots behind.''
Martin Kaymer made a lot of players feel that way Friday with a second straight 65 to set the U.S. Open's 36-hole scoring record at 10-under 130.
Everyone else made this feel like a regular U.S. Open.
''You always think Thursday, Friday (that) 3, 4, 5 under probably is going to be leading,'' Johnson said. ''But obviously, Martin is playing very well. And that 10 under is very good around here for two rounds.''
There still are two days remaining, although it appears more daunting when a former major champion and world No. 1 is atop the leaderboard by such a big margin.
Johnson, however, knows from experience that strange things happen at the toughest test in golf.
Four years ago at Pebble Beach, Johnson took a three-shot lead into the final round.
It was gone in two holes.
He got such an awkward like in the finger of a bunker that he tried to play it left-handed and wound up with a triple bogey. On the next hole, he drilled a driver into a bush and the ball was never found. And then he hit driver into the ocean. Johnson shot 82 that day.
''Anything can happen,'' Johnson said. ''As you all know, anything can happen in a U.S. Open. This golf course is tough. If you get just a little bit off with your driver and your irons, you're going to have a long day. I've got a good game plan. I'm going to stick to it. If I keep hitting it like I am, then I'm going to keep shooting good scores.''
Johnson picked up four bogeys on Friday, and only one of them annoyed him. His long birdie putt on the par-3 sixth hole went just under 3 feet past the hole. The par putt caught the lip, and Johnson had a slightly longer putt that he made for his bogey.
''Other than that, I thought that I played really solid and put myself in good spots all day,'' he said.
At least he won't be in the same group as Kaymer. They are linked to Whistling Straits - even though they weren't paired together - at the 2010 PGA Championship. Johnson had a one-shot lead playing the final hole when he grounded his club in sand that he didn't realize was a bunker. It was well outside the ropes, where fans were walking.
Johnson made bogey, the penalty gave him a triple bogey, and he missed out on a playoff that Kaymer won.
They faced each other in the Ryder Cup at Wales later that year, and Johnson beat him, 6 and 4. That feels like the margin that Kaymer enjoys now in stroke play.
Big leads are not always easy, however.
Adam Scott can speak from experience, too. He had a seven-shot lead going into the weekend in the Arnold Palmer Invitational at Bay Hill and wound up with 71-76 to finish two shots behind.
Scott referred to Kaymer's lead as ''considerable.'' His advice for Kaymer was ''don't play like you're leading.''
''That doesn't mean play aggressively or do anything stupid, but I don't know why he would change anything of what he's doing,'' Scott said. ''Potentially, he goes out tomorrow and plays better than everyone again and this thing's over. So just keep doing what you're doing and enjoy it, enjoy that position.''