Chris Kirk surged into a share of the lead at the Hyundai Tournament of Champions in Hawaii after birdieing the last five holes of his first round.
Kirk carded a seven-under-par 66 to sit alongside Webb Simpson, Michael Thompson and Jordan Spieth at the top of a congested leaderboard, one clear of four more players on six under.
That group includes Kevin Streelman, who looked for a long time like he would end the day clear at the top, but unlike many of his colleagues he struggled on the closing holes, dropping shots at 17 and 18.
Kirk was an unspectacular two under through 13 holes before his spectacular run catapulted him into the leading quartet.
The last five holes were generous to the leaders - Spieth and Thompson each had four birdies in the last five, while Simpson picked up three.
"It's a course that I shouldn't make a lot of bogeys on if you keep the ball in play and just think your way around the course," Spieth said.
"Ultimately, I did some good preparation and did a lot of hard work the last two or three weeks getting ready for today, and now just happy to be in good position after the first round."
For Streelman it was a different story - he was five under after carding eagles at the third and fifth, but he bogeyed the sixth and played the last five in one over, putting him down in a share of fifth.
He was joined on six under by Jason Dufner, Zach Johnson and Ryan Moore. Scotland's Martin Laird was the leading European in a share of 18th on two under, with only two of the 30-strong field over par.