The world number three, who ended last year as the European Tour's top golfer, is joint fifth at the event for players who won on the PGA Tour in 2019.

Chile's Joaquin Niemann shot a seven-under 66 to lead American Justin Thomas by one, with compatriots Matt Kuchar and Rickie Fowler at five under.

Northern Ireland's Graeme McDowell and England's Paul Casey are both one over.

Niemann was part of the International team that lost to the United States in the Presidents Cup last month and the 21-year-old says that, despite not winning a match during the contest, he gained invaluable experience.

"I think the Presidents Cup was huge for me, for my career, for my future," he said.

"I think during that week I learned a lot, I was with the best players in the world, I was team-mates with Adam Scott. I talked a lot with them. It was an unbelievable week."

Former world number one and two-time winner Dustin Johnson had a rollercoaster round, carding five birdies and an eagle along with a double-bogey seven at the par-five ninth and four bogeys en route to a one-under 72.