Masters champion Bubba Watson was six shots off the clubhouse lead after his opening round in the defence of his Zurich Classic title.
Watson carded a one-under-par 71 to sit well off the pace of fellow American pair Ken Duke and Cameron Tringale in New Orleans.
The 33-year-old had four birdies and three bogeys in an up-and-down round on his return to action following his play-off success at Augusta earlier this month.
Duke, in contrast, racked up seven birdies in a flawless round, while Tringale had eight, including four in a row from the 15th hole, and one bogey.
Sweden's Daniel Chopra and another American Steve Stricker were one shot behind after going round in 66, while American pair Ben Curtis and John Rollins were in the clubhouse on five under.
Northern Ireland's Graeme McDowell was the highest-placed British or Irish player on three under.
Starting on the back nine, he did not have a par until his 10th hole as he carded eight birdies and five bogeys.
