American Boo Weekley and Zimbabwe's Brendon de Jonge carded a first-round 64 to take a share of the lead after day one at the Zurich Classic of New Orleans.
Weekley got off to a fine start at TPC Louisiana, picking up an eagle at the second before holing a further seven birdies and one bogey to finish Thursday at eight-under-par.
There were similar heroics from De Jonge, who sank eight birdies in a bogey-free round as the duo both enjoyed prolific starts to the tournament.
The pair are being pursued by American Sean O'Hair and Canada's David Hearn, who shot a seven-under-par 65 to finish up one shot off the pace.
Englishman Brian Davis is among those in a four-way tie for third along with United States trio Daniel Berger, Erik Compton and Mark Hubbard, who all sit one stroke back.
Elsewhere, Jason Day and Dustin Johnson are two of the stand-out players in a 10-way tie for fourth on five-under.