Dustin Johnson maintained the momentum from ending a five-month barren stretch by taking the overnight lead at the Dell Technologies Championship.
After winning the Northern Trust tournament in New York, last week, Johnson kept in the groove in Boston after a five-under-par 66 saw him take a one-shot advantage from the first round’s play.
The world number one made short work of a tough course after starting his round with a 35-foot birdie putt on the 10th and then heading into the turn at four under, following an eagle at the 18th.
"When you win, you're playing well, so it gives you a lot of confidence," Johnson said.
"For me, that was one thing that was probably lacking a little bit the last few months is just the confidence, because I wasn't seeing the shots that I wanted to see. I wasn't consistently hitting them.
“But after last week, I've got a lot of confidence now. I feel like the things I've been working on, they are back to working."
Masters champion Sergio Garcia is one of four players within a shot of Johnson after the Spaniard sank five birdies on the front nine.
Garcia is joined at four under by Marc Leishman, Kyle Stanley and Jon Rahm after the latter birdied four of his last five holes.
In his final tournament before the President’s Cup picks, Phil Mickelson also enjoyed a welcome return to form. The veteran American lies at three under par – the first time he has broken par in a round since early July.
Mickelson said: "It was nice to have a solid round. I played well tee-to-green, and it made for a stress-free day on a very difficult day."
The pros at the Sony Open in Hawaii were sent scrambling for cover on Saturday after a ballistic missile alert was sent out by mistake.