Patrick Cantlay racked up six birdies and Rory McIlroy played a bogey-free round on their ways to five-under-par 65s to share the first-round lead at the US Open in Pinehurst.
Cantlay established the lead early in the day, and McIlroy, the 2011 champion, had birdies on two of the final three holes playing in the afternoon.
Sweden's Ludvig Aberg shot 66 to hold third place.
