Martin Kaymer found top form in the closing stages of the opening day of the US Open as he carded a 65 to earn a three-shot lead at Pinehurst.
The German started his back nine sitting comfortably on one-under-par, before birdies at 10, 14, 16 and 17 allowed him to move clear of his rivals in North Carolina.
For long periods of the day it appeared that a number of players would be level at the top of the leaderboard before Kaymer's late surge.
Graeme McDowell and Kevin Na, who were among the players to go out early in the day, shared the lead for most of the afternoon on two-under, and were eventually joined on the same score by Brendon de Jonge and Fran Quinn.
A big group of players, including Henrik Stenson and Matt Kuchar, are one shot further back, while defending champion Justin Rose endured a difficult start to the competition before eventually coming in at two-over.
Callum Mulvihill
