By Mark Lamport-Stokes

OAKMONT, Pennsylvania (Reuters) - Dustin Johnson ended a marathon Friday at the weather-disrupted U.S. Open with the clubhouse lead, carding one-under-par 69 shortly before second-round play was suspended for the day in fading light.

The long-hitting American, who missed a three-foot putt at the final hole to hand last year's U.S. Open to Jordan Spieth, produced superb form from tee to green to post a four-under total of 136 at Oakmont Country Club.

Also at four-under was surprise first round leader Andrew Landry, a PGA Tour rookie who will only start the second round on Saturday morning after the year's second major championship was knocked off schedule by multiple thunderstorms on Thursday.

Johnson could have been further ahead as he missed several birdie putts from 10 feet and in on a sun-splashed afternoon and had to settle for a two-shot advantage over compatriot Scott Piercy (70) and Spaniard Sergio Garcia (70).

England's Andy Sullivan (68) was a further stroke back with American Daniel Summerhays, who fired the best score of the week with a seven-birdie 65 to surge up the leaderboard.

Among the big names at Oakmont, Australian Adam Scott was even after 15 holes, while world number one Jason Day, playing in the same group, was five over.

Fifty-one players completed the second round on Friday.

Spieth (first-round 72) and third-ranked Northern Irishman Rory McIlroy (77) are among half the field who will start the second round on Saturday.

"It was a long day today, but I felt like I played really solid all day for all 36 holes," said world number six Johnson, who had opened with a bogey-free 67 earlier on Friday.

"I drove it really well. Hit a lot of great iron shots. Felt like I rolled the putter really nicely too, so very pleased with how it went today."


As the treacherous Oakmont layout began to firm up under a blazing sun after being softened by heavy rain earlier in the week, Johnson said that putting became much more of a lottery.

"No matter how close you are to the hole, they're tough to putt," said the 31-year-old, a nine-times winner on the PGA Tour who is still seeking a first major title after several close calls.

"I mean, I hit so many good putts today that I thought were going in, and burned the edge or lipped out. But that's just how it goes. These greens are tough."

Garcia, like Johnson seeking his first grand slam crown after several near-misses in the past, was happy to finish at two under on a course he rates as the toughest in the world.

"I didn't play that great this afternoon but I thought I scrambled nicely and I made a couple big putts when I needed to," said the Spaniard, who ended his round by draining a 50-footer for par.

"Definitely the toughest I've ever played. I'm very happy to finish at two-under."

Organizers hope to get the second round finished by early afternoon on Saturday, before completing the third round by the end of the day. Weather conditions look favorable for the entire weekend.

(Editing by Andrew Both)