Spieth hit a bump-and-run from 100 feet to set up a birdie on the par-5 11th, he chipped in for birdie on the 14th and closed out the round with a 15-foot birdie putt on the par-5 18th at the TPC Louisiana.
They were tied with 18-year-old Ryan Ruffels and Kyle Stanley.
Nick Watney made a 60-foot eagle putt from off the 18th green for eagle as he and Charley Hoffman were among four teams at 67 in alternate shot.
Paducah Tilghman alum Kyle Ramey, and his partner Phil Schmitt, shot an opening round 75. They're tied for 73rd at 3 over. This is Ramey's his first PGA Tour event.