Mickelson rallied with two pars, which offered a return to normalcy that he had needed. But then he severely hooked his tee shot at the par-5 16th and watched helplessly as it bounded into the course’s thick native grasses. The ball came to rest beside the front tire of a golf cart parked atop a sandy mound.
The cart was moved, and Mickelson punched out, and he then found the green with his third shot. His 12-foot birdie putt was struck too firmly, though, and while it hit the hole, it was traveling so fast that it hopped over the cup and lipped out.
Minutes earlier, on the 16th green, Koepka had rolled in a birdie putt that pulled him into a tie for the lead at seven under. His stay alongside Mickelson in first was brief, however; Koepka missed a 6-foot par putt on the 18th hole as his rival parred in.
“It felt like the worst putting performance I’ve ever had,” said Koepka, who has won four major championships, and two P.G.A. Championships, since 2017. “The only way to look at it is that it can’t get any worse.”
While Koepka was on his way to a bogey at 18, Mickelson, on the par-3 17th hole, the most intimidating spot on the course, drilled an impressive iron from the tee to within 17 feet of the cup. He settled for par when his birdie putt trickled just left of the hole, but on the final hole of the day, despite missing the green to the left, he nearly chipped in from 65 feet. His 5-foot par rolled around the edge of the cup but dropped in for his final par.
Mickelson opened Saturday’s round by slicing his first tee shot into rough so thick his caddie, and brother, Tim could not find the ball even when standing only eight feet away. Nearby fans pointed it out. When Phil Mickelson later arrived on the scene and gazed down at his ball, he chuckled.