A late birdie helped Dustin Johnson retain a share of the Pebble Beach Pro-Am lead as Ted Potter Jr. surged in stunning fashion on Saturday.
World number one Johnson carded a two-under 70 on Pebble Beach Golf Links to sit at 14 under after the third round.
The American, a two-time winner of the PGA Tour event, was four under through seven holes, but he struggled on the back nine before making a 10-footer for birdie at 18.
Johnson held a share of the overnight lead and, alongside Potter, the duo will carry a two-shot advantage into the final round.
The day belonged to Potter - whose only PGA Tour win came in 2012 - as he fired a nine-under 62 on the Monterey Peninsula Country Club course.
Lowest round of the day.-- PGA TOUR (@PGATOUR) February 10, 2018
Lowest round of his career.
Moving Day for Ted Potter, Jr. pic.twitter.com/jsSU9ds9VF
Beginning on the back nine, Potter made four straight birdies and another at 15 before an eagle at 16.
He was flirting with a 59 after another four birdies to start the front nine, but he finished bogey-bogey.
Australian Jason Day (69 on Pebble Beach) and Troy Merritt (69 on Monterey) are tied for third at 12 under.
A shot behind them are Spanish world number two Jon Rahm, Steve Stricker and Patrick Rodgers.
Four-time champion Phil Mickelson continued his strong showing with a 72 on Pebble Beach leaving him in a tie for ninth.
Last year's winner, Jordan Spieth, is at seven under, while Rory McIlroy's first appearance on the PGA Tour this season saw him miss the cut.