Johnson, Stenson hit the front

 Dustin Johnson and Henrik Stenson set the first-round pace at the US Open on Thursday on a day of remarkable highs and lows as Tiger Woods shot an 80, his fourth-worst score as a professional.

American Johnson and Swede Stenson fired matching five-under-par 65s on a firm and fast-running Chambers Bay layout while Phil Mickelson made an encouraging start with a 69.

The long-hitting Johnson piled up six birdies and a lone bogey to finish level with Stenson, who birdied four of his last five holes at the British Open-style venue in the year's second major, being played for the first time in the Pacific Northwest.

They were one stroke ahead of American Patrick Reed, while Americans Matt Kuchar, Ben Martin and amateur Brian Campbell trailed by two.

"I hit the ball really well ... had a lot of good looks at birdie all day," Johnson, who like Stenson is seeking a first major title, told reporters.

"It's firm but you could control your golf ball, for sure. Today I controlled my ball very well. The confidence is definitely there. I feel really good about where I'm at and going into tomorrow."

Mickelson, who is yearning to complete a career Grand Slam of the four majors by winning his first US Open, was "very pleased" after a round that included four birdies and three bogeys.

"I hit a lot of good shots today," Mickelson, a runner-up at the US Open a record six times, said. "I shot under par the first day of the US Open.

It was an average morning for Northern Ireland's World No 1 Rory McIlroy. Seeking his fifth major victory, he birdied his second hole but never got into top gear as he struggled on the greens to return a 72.

"I need to find a rhythm in my stroke over the next three days, work a bit on the putting green," said McIlroy. "Hopefully it will be better tomorrow."

Masters champion Jordan Spieth, who played in the more difficult conditions of the afternoon as the course firmed up, was delighted to open with a 68.

Poor start

The Indian challenge got off to a disastrous start with both Shiv Kapur and Anirban Lahiri faltering. While Kapur carded two-over 72, Lahiri made five-over 75.

Leading scores (after 18 holes, US unless mentioned): 65: Dustin Johnson, Henrik Stenson (Swe); 66: Patrick Reed; 67: Matt Kuchar, Ben Martin, Brian Campbell; 68: Cody Gribble, Jason Dufner, Jordan Spieth, Joost Luiten (Ned), Francesco Molinari (Ita), Marc Warren (Sco), Jason Day (Aus).