Max Homa shot a three under 68 at the Genesis Invitational on Friday to take the lead headed into the weekend.
After sharing the lead with Keith Mitchell at the close of the opening round, Homa relied on a flurry of birdies at the turn in his second trip around The Riviera Country Club to claim a solo one-stroke advantage.
The American battled through a pair of early bogeys to pick up shots on the ninth, 10th, 11th and 13th en route to an overall score of 10 under.
Meanwhile, Mitchell remains hot on Homa’s heels at nine under, alongside Jon Rahm and Lee Hodges.
Northern Ireland’s Rory McIlroy fell back a bit on Friday with a 69, however he remains in the hunt on six under par.
Victory for McIlroy would see him overhaul Scottie Scheffler as world number one regardless of the latter’s result, while outright third place would be good enough for him unless the American finishes in the top 25 or Rahm wins or is outright second.
England’s Danny Willett is a shot further back, while compatriot Tommy Fleetwood and Ireland’s Shane Lowry are among a host of players on four under.
The second round will resume early on Saturday after play was suspended due to darkness.