Johnson stays in lead as Potter flirts with 59

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.

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.