|RBC Heritage first-round leaderboard|
|-8: B Cauley (US); -6: L Donald (Eng), G De Laet (Can), S Saunders (US); -5: S Lowry (Ire), R Henley (US), D Lee (NZ), I Poulter (Eng), B Crane (US), W Simpson (US)|
|Selected others: -3: M Kaymer (Ger), B Grace (SA), M Kuchar (US), A Johnston (Eng); -2: T Hatton (Eng), M Laird (Sco); -1: R Knox (Sco); level: D Willett (Eng)|
Luke Donald shot a six-under-par 65 to be tied second after day one of the PGA Tour's RBC Heritage in South Carolina.
The world number 96 carded five birdies, an eagle and dropped just one shot to join Canada's Graham de Laet and American Sam Saunders in second.
American Bud Cauley leads on eight under, dropping no shots in his round.
England's Ian Poulter produced one of the lowest rounds of his season to reach five under, with Ireland's Shane Lowry tied fourth on the same mark.
Danny Willett - who missed the cut as defending champion at the Masters last week - described his level-par start as "steady".
Englishman Donald - who was world number one in 2011 - last won on the Japan Tour in 2013, with his most recent PGA Tour victory arriving at the Transitions Championship in March 2012.
But he has finished second at this event - held at Harbour Town Golf Links - four times in the past eight years.
"Obviously, I've had a lot of success here in the last eight years, done everything but win," said Donald.
"It would be nice to give myself another chance to try and finally get over that hurdle."
The 39-year-old started the day on the back nine but after turning in three under, produced an eagle on the second hole when his 209-yard approach left a short putt.
Cauley, 27, sat out all of the 2015 season after shoulder surgery and has missed the cut on his last two outings.
But he needed just one putt on each of the last three holes to convert successive birdies and in doing so secured a two-shot lead going into Friday's second round.
Last year's winner Branden Grace is tied for 19th on two under.