Rose struggles in title defence
Justin Rose discovered just why it has been 25 years since anyone won back-to-back US Open titles on Thursday, despite Pinehurst playing easier than expected for the early starters.
While Brandt Snedeker raced to the turn in 31 - which could have been 30 had he not missed from five feet on the ninth - Rose covered the back nine in four over par to lie seven shots off the lead.
Curtis Strange was the last man to successfully defend the title in 1989 and the former Ryder Cup captain's place in the history books looked increasingly secure as Rose dropped shots on the 13th, 14th, 17th and 18th.
In contrast Snedeker had birdied the first, fifth, seventh and eighth to reach four under par, only to then bogey the 10th and double-bogey the 11th, where he three-putted from long range after his third shot came up just short of the green.
That left compatriot Matt Kuchar in the lead on three under, the world number five having birdied the first, fifth and ninth to be out in 32.
Former champion Graeme McDowell was one under par after recovering from a bogey on the fourth with an eagle on the fifth, the 2010 winner holing from 10 feet after a three-wood approach from 248 yards.
The tee on the fifth had been brought forward by 48 yards and the course as a whole was playing 202 yards shorter than the maximum, although it still took nine holes for Rory McIlroy to find his first birdie of the day.
Playing alongside his fellow Northern Irishman McDowell, McIlroy had missed from four feet on the second, a "turtleback" green which he had predicted would only be hit 20 per cent of the time this week.
The former world number one then dropped shots on the sixth and seventh after failing to get up and down from sand, before holing from eight feet on the ninth.
After almost four hours of play, a total of 17 players were under par, including teenage amateur Matt Fitzpatrick and Open champion Phil Mickelson, who were playing alongside Rose.
Fitzpatrick, who won the US Amateur last year but will make his professional debut in the Irish Open next week, had carded three birdies and two bogeys on the back nine, while Mickelson collected two birdies and one bogey to also be out in 34.
Mickelson has finished runner-up in the event six times, including to Rose 12 months ago, and needs to win to become just the sixth player in history to win all four major titles.