Day, who has been struggling with issues of dizziness for several weeks, crumpled to the ground and stayed there for several minutes while being attended to by his caddie and officials. His wife, Ellie, also was there. He did not appear to lose consciousness.
Day eventually got up and unsteadily walked to the shot he had hit into the bunker of the par-3 hole. He blasted the shot onto the green and missed the par putt to make bogey to finish with a 70 that put him in a tie for 11th place.
As Day left the green, he knelt down on one knee, got up and then walked to a waiting cart, which transported him to the scoring area. From there, he was picked up by a van and taken away.
Playing partner Jordan Spieth told Fox, "I turned around, and he was laying down there. All I heard is that it was dizziness. ... For him to go finish the round … he could barely stand up … was strong of him."
Day, who won the Farmers Insurance Open at Torrey Pines in February, was first affected by dizziness in the final round of the Zurich Classic in New Orleans in April. The 27-year-old then went 0-for-3 in the WGC-Match Play Championship in his title defense. He then missed the cut in the Players Championship and Memorial.