Pinehurst - Germany's Martin Kaymer, coming off a victory in last month's Players Championship, charged to the top of the leaderboard late in Thursday's first round of the US Open at Pinehurst.
Kaymer birdied the 14th hole to stand on three-under par with four holes remaining, one stroke in front of clubhouse co-leaders Kevin Na and Graeme McDowell.
Also at two-under was South African Brendon de Jonge, who has only one top-10 showing in 20 US PGA starts this season. De Jonge, still seeking his first US triumph, had two holes to play.
Kaymer, the 2011 PGA Championship winner, opened with a birdie, added another at the par-5 fifth, took a bogey at seven and then struck on the back nine with birdies at the par-5 10th and 14.
De Jonge, who began on the back nine, opened with back-to-back bogeys but battled back with birdies at 14, 16 and 17 and birdied the fifth as well.