Patrick Cantlay shot a blemish-free round of 65 to take a share of the lead with Patrick Reed after the opening round of the Hero World Challenge in the Bahamas.
Cantlay's short game was on fine form in New Providence as he carded seven birdies on Thursday, the world number 20 finishing with a flourish and he charged up the leaderboard.
Five birdies in his final six holes capped off a fine debut at the event for Cantlay – who will donate $500 to the families affected by the California wildfires for every gain he makes over the four days.
He is joined at the summit by Reed, who would have enjoyed the outright lead but for a dropped shot at the eighth.
The pair have a three-shot advantage over the field with Henrik Stenson and Dustin Johnson the nearest challengers on four under.
Alex Noren (-3) and Justin Rose (-2) both had a share of the lead at some point during the opening day, but both slipped back with costly dropped shots on the back nine.
Only three of the 18 players in action failed to finish under par, one of which was host Tiger Woods.
After falling to two over through five, Woods quickly got himself back to level par by the turn but a triple bogey at the par-three 12th cost him dearly.
Having pulled his tee shot, Woods' second saw the ball fail to reach the green and spin back down the slope and into the water.
He subsequently two-putted to sign for a six, but his day improved with gains at 15 and 18 to finish with a one-over 73.
"I just didn't quite feel comfortable with my game and it was reflected in my scoring," Woods said after his frustrating start.