Justin Rose briefly moved into a tie for first with a tricky 14-foot putt on No. 4 just as Tiger Woods watched his delicate chip on No. 6 check up short and roll back, setting up a bogey that left him at five over, a backslide of two strokes from his starting point on the day.

Rory McIlroy was faring even worse, standing at six over, and leaving the chances increasingly slim that either of the world’s two best players would be a factor in this year’s U.S. Open.

As for the rest of the field, they could take solace in the fact that no one had played well enough to pull away. If the whole point of moving day is to put yourself in position for a Sunday afternoon challenge, there were still a dozen players within four strokes of the leaders late Saturday afternoon.

--David Wharton

Phil Mickelson, Billy Horschel begin third round | 12:40 p.m.

Phil Mickelson is on the course at Merion Golf Club and settled at the first hole for what should be the most comforting three words he'll hear all day: "Tap-in par."

Yes, Mickelson just missed his birdie chance at the par-four No. 1 but he'll keep his stress level low if he can keep making easy pars on a course that is spitting out a lot of bogeys during the 113th U.S. Open.

Co-leader Billy Horschel also made par at the first.

Mickelson hit his drive on the par-five second into thick rough, forcing a layup ... into the rough. He chopped his third shot to the green but missed another makeable birdie putt.

It was another solid par but Mickelson knows he could be winning this thing in a runaway if only he had made a few more mid-range putts.

On a course as tough as Merion, though, he's got to keep telling himself that par is OK and wait for the occassional gift.

Mickelson went all day without a birdie in the second round before rolling in a 21-footer at the 18th.

Meanwhile, Horschel hit a perfect drive on No. 2 but shank-hooked his second shot to the left and then chunked his third into the bunker. He made a beautiful up-and-down from there to save par and keep a share of the lead.

Look out for: John Senden. The Australian birdied his first two holes to join the leaders at one under. Senden is a solid ball striker who has been plagued by his putting. So far, so steady.  Senden's only win on the PGA Tour was at the John Deere Classic in 2006. He's a four-time winner in international events.

Not so fast on that Tiger Woods-Rory McIlroy charge. Both got tripped up at the sensationally long, 256-yard par-three third hole. Both superstars came up short and missed par putts. McIlroy followed his opening birdie with two bogeys.

Woods was still three over par through four holes, same as he started the day. McIlroy has given back a shot and is four over.

Take your shoes off, but don't relax: Charley Hoffman removed his shoes and rolled up his pants to hit his third shot on the par-five fourth hole. Hoffman then chipped in for a birdie. A birdie at four is some achievement as the 600-plus-yard par-five hole is playing to an average of 5.3 shots this week.

Tiger Woods opens third round with a birdie | 11:45 a.m.

That gulp you just heard might have been from the top of the leaderboard after Rory McIlroy and Tiger Woods opened their third rounds with birdies at the par-four first hole.

Woods and McIlroy, the top two ranked players in the world, started the day four shots back of co-leaders Phil Mickelson and Billy Horschel, who completed 36 holes at one-under-par 139.