Elsewhere, Northern Ireland’s Rory McIlroy is in a share of 10th place on six under after an opening 69.
He began the tournament on four under, but he made four birdies, as well as two bogeys, to complete his first round two shots better off.
“I’m happy with how I hung in there and had a good finish,” McIlroy told Sky Sports.
“When I saw Scottie had got to 14, I was like, ‘oh, got to try to just hang on to the coat-tails a little bit’.
“I still feel like I’ve got a chance, and it was nice to finish the way I did.”
Of the two Englishmen in the 30-man field, Ryder Cup star Tommy Fleetwood is on two under after an opening 70, but Wolverhampton’s Aaron Rai, playing in this season-closing event for the first time after a fine run of form, shot a five-under 66 to sit a shot behind McIlroy, tied for 14th.
Scattered thunderstorms are forecast for Friday’s second round.
There is no 36-hole cut for the tournament, while the winner after 72 holes will take home the FedEx Cup and a $25m (£19m) prize.