Rickie Fowler and Bryson DeChambeau took a share of the lead at the halfway stage of the Waste Management Phoenix Open after both shot rounds of 66 on Friday.
DeChambeau birdied the final two holes, while Fowler bogeyed the 17th but was helped by a run of four birdies in six holes on the front nine, including a stunning approach to the sixth.
A 191,400-strong crowd turned out to see the Americans go into the third day 10 under with fellow compatriots Daniel Berger and Chez Reavie a stroke back.
Berger and Reavie both signed for bogey-free rounds of 65, with Reavie carding an eagle on the driveable 17th.
Americans make up the top seven on the leaderboard, with Chesson Hadley, Scott Stallings and Chris Kirk all eight under.
Scot Martin Laird is then in the group at seven under alongside world number two Jon Rahm after a 67.
Robert Garrigus had spectators in a frenzy after almost making an ace on the par-four 17th, the flag-pole being the only thing to deny him the hole-in-one. He went on to card an eagle, finishing two under for his first two rounds.