A chip-in on the 15th hole propelled Jason Day to the outright lead on his way to a seven-under 63 in the opening round of the Wells Fargo Championship.
After a solid front nine, where he birdied three of his first five holes, it was an action-packed second nine. He birdied 10, 12, 14, 15 and 16, with his sole bogey coming on the 13th.
Only posting three top-10 finishes from 22 events last season – with a best result of tied-seventh – Day is already in search of his third top-10 result this season in his 11th event, seemingly rediscovering some of the form that has seen him spend 51 weeks as the world number one.
Speaking to the media after stepping off the 18th green, Day was careful to not get ahead of himself, but emphasised his focus on creativity as opposed to just technique.
"I'm obviously, I think, a long way away from being that confident in myself in regards to my game," he said.
"But I feel like [with what I've worked on with my swing] I'm a little bit more creative on the golf course, because at some point you have to get out of the technical aspect and go more creative.
"I feel like things are progressing nicely, and I just have to keep my head down and keep going.
"It is actually very encouraging [to be healthy and confident in his body] because typically if I play well, then people ask me how my back is, and that's probably not something you want to always constantly want to be talking about.
"I've done a lot of work, and been very diligent and disciplined in my approach to staying healthy. I get hiccups every now and then, but for the most part – touch wood – I've been really good."
There was a spectacular start to the day for American Joel Dahmen, who was six under through eight holes, including four consecutive birdies starting on the fifth, before cooling off and finishing at six under for outright second.
One shot further back in the group tied for third were England's Aaron Rai and Callum Tarren, who had just one bogey between them.
Rickie Fowler highlighted the next group at four under after coming back from one over through eight holes, with four birdies, one eagle and one bogey in the last 10.
Fowler sat one stroke ahead of a logjam at three under, which included defending champion Rory McIlroy, Sergio Garcia, Max Homa and Matt Kuchar, with England's Matt Fitzpatrick and India's Anirban Lahiri at two under.