Ricky Barnes leads the Zurich Classic by one shot after recording a score of 64 for his opening round in New Orleans.
The American hit seven birdies and an eagle to hold a slender lead over compatriots Boo Weekley and Lucas Glover.
DA Points and Morgan Hoffman were a shot further adrift on six-under-par, while Ernie Els and Rickie Fowler headed a group of 10 players on five-under.
As many as 15 players, including Englishmen Justin Rose and Brian Davis, opened up with a 68, with American Keegan Bradley in contention on three-under-par.
Guan Tianlang, the 14-year-old from China who made headlines in making the cut at The Masters in Augusta two weeks ago, recorded a level-par round of 72.