By Mark Lamport-Stokes

OAKMONT, Pennsylvania (Reuters) - Little-known American Andrew Landry upstaged the game's biggest names on a frustrating day of multiple weather delays as he grabbed an early one-shot lead in the abbreviated first round of the U.S. Open on Thursday.

The 28-year-old PGA Tour rookie, competing for the first time in the year's second major, carded five birdies and two bogeys in 17 holes on a rain-softened but still brutal course at Oakmont Country Club outside Pittsburgh to get to three under.

Benefiting from accurate driving on a layout known as one of the most treacherous in golf, Landry was lining up a 10-foot birdie putt on his final hole, the par-four ninth, when the horn sounded to suspend play for a third time.

Just over half an hour later, play was suspended for the day as lightning strikes flashed, thunder rumbled and heavy rain swept across the course.

Twice Masters champion Bubba Watson, after 14 holes, and New Zealand's Danny Lee, after 13, were both at two under on a day when thunderstorms and heavy rain had already wiped out more than three-and-three-quarter hours of scheduled play.

Among the big names, defending champion Jordan Spieth was at one over after 11 holes, 2011 champion Rory McIlroy was four over after 13 and Masters champion Danny Willett four over after 12.

Only nine players completed the opening round and the best of them was American amateur Scottie Scheffler who, at the age of 19 in his first U.S. Open, carded a one-under 69 to hold the clubhouse lead.

"It was tough," Landry, whose best PGA Tour finish was a tie for 41st at the FedEx St. Jude Classic on Sunday, told reporters about how he handled his on-off-on-off day.

"Had my family here with me, and just kind of kept to myself, went to the locker room, stayed by myself, talked with my caddie a little bit and had my phone off the whole time.

"I've hit the ball really well today and just made a bunch of putts, and just kept it going."

SURVIVED QUALIFYING PLAYOFF

Scheffler, who survived a six-man playoff in sectional qualifying to earn a spot in this week's field of 156, was delighted to get his round in before play ended for the day.

"Three more rounds to go," said the University of Texas standout. "My game plan isn't going to change too much.

"Try to get the ball in play and see what I can do on the fairways out here. It's not easy to play from the rough and the bad spots around this course."

Level with Scheffler at one under were England's former world number one Lee Westwood, who had completed 13 holes, and Americans Kevin Streelman, after 16, and Harris English, after 12.

"It's obviously a frustrating day having to keep coming off, but there's nothing you can do about the weather," Westwood said after mixing an eagle two at the par-four 14th with two birdies and three bogeys.

"I'm playing well though, playing nicely. I've dropped shots when I've missed it in the wrong spots and made some nice birdies too."

Organizers said the opening round would resume at 7.30 a.m. ET (1130 GMT) on Friday with the hope of starting round two from around 2 p.m.

Among those players yet to tee off in the 116th U.S. Open are Australian world number one Jason Day and American fan favorite Phil Mickelson, a runner-up in his national championship a record six times without ever winning the title.

Thursday's opening round had been destined to spill over into Friday after a weather delay in mid-morning of just over an hour and a quarter while a line of storms passed through the area.

The treacherous Oakmont layout, known for its lightning-fast greens and sloping contours, had been softened by more than an inch (2.5 cm) of rain overnight and further thunderstorms had always been expected for Thursday afternoon.

Weather conditions are, however, expected to improve from Friday morning onwards with mainly sunshine forecast for the weekend.

(Editing by Larry Fine)