Bubba Watson set the early pace as he went in search of a third World Golf Championships title at the WGC-FedEx St. Jude Invitational.
The event was making its first appearance at TPC Southwind with 45 of the top 50 in the Official World Golf Ranking in attendance, and Watson turned in 31 to get to four under.
Canadian Corey Conners, 2017 champion Hideki Matsuyama and two time reigning Australian PGA Championship winner Cameron Smith were a shot off the lead, one clear of a large group that included Tyrrell Hatton, Jon Rahm, Justin Harding, Alex Noren, Ian Poulter and Justin Rose.
Hatton bogeyed the first after missing the green and failing to get up and down but hit an approach to eight feet on the second and took advantage of the par five third to get into red numbers.
An approach to seven feet edged him further up the leaderboard and a brilliant 25 foot putt on the par three eighth had him in a seven way tie for the lead.
Watson was in that group as he got inside ten feet at the second, made a birdie at the first par five and then holed from 14 feet at the fifth.
A stunning tee shot to three feet on the eighth then edged him ahead and Hatton found himself two behind as he missed the green on the ninth.