After two rounds at The American Express it is Davis Thompson and Jon Rahm who have broken away from the field, both at least three strokes clear of third place.
Thompson was the first-round leader after riding back-to-back eagles to a 10-under 62 – the best score of his PGA Tour career – and he added three more eagles in his second round to follow it up with a 64 and head into the weekend at 18 under. His five eagles ties the PGA Tour record for the most through 36 holes at any event.
He is two strokes clear of Rahm at 16 under after the world number four went bogey-free for his second 64 in a row.
Both players began their week on the La Quinta Country Club course, and both played the PGA West's Nicklaus Tournament course on Friday. They will play Saturday's round on the PGA West Stadium Course, which is also where Sunday's final round will be contested.
There are some big names in the chasing pack, with South Korean rising star Tom Kim and former world number one Jason Day part of a five-man group at 13 under.
Patton Kizzire is alone in eighth at 12 under, while world number six Xander Schauffele rounds out the top-10 in a tie for ninth at 11 under.
World number two Scottie Scheffler and number five Patrick Cantlay are still in the hunt at 10 under, while number seven Will Zalatoris is one shot inside the theoretical cut line at six under, but all players will get one more round before the cut at the conclusion of round three.