Simpson edges in front
Webb Simpson was a shot clear of the field heading into the final four holes of his first round at the Wells Fargo Championship in Charlotte.
The 26-year-old from North Carolina carded five birdies over a flawless first 14 holes, the highlight coming with an eagle two at the eighth.
His fellow Americans Rickie Fowler, DA Points and Patrick Reed, along with England's Brian Davis and Australian John Senden, were a shot back in the clubhouse after opening with 66s at Quail Hollow. Ryan Moore was also six under through 17.
Billy Mayfair, Brian Harman and Zimbabwe's Brendon de Jonge were a shot back after 67s.
England's world number three Lee Westwood - playing with a new caddie in American Casey Kerr after regular bagman Billy Foster injured his knee before a charity football match on Monday - was among a large group six shots off the pace, which also included Phil Mickelson, after posting a one-under-par 71.
US Open champion Rory McIlroy was two under through 13, the Northern Irishman blotting his copybook by bogeying the par-four fourth, while Tiger Woods was level par through 14 at his first tournament appearance since the Masters four weeks ago.