On Friday, Jason Day gave everyone a scare by collapsing on the green in his final hole in the second round of the U.S. Open. He was eventually diagnosed with Benign Positional Vertigo, but was still uncertain whether he would be able return to action over the weekend. The very next day, he would make an improbable run that would give him a share of the lead.

Day finished 2-under 68 for the day, one of only six under-par rounds at the time of his finish, as noted by Yahoo Sports. After Round 2, he was three strokes off the lead, but after birdieing the 17th and 18th holes, he now finds himself at 4-under, and tied with Jordan Spieth, Dustin Johnson, and Branden Grace.

"I didn't feel great coming out early," Day said of having to battle with dizziness at the start of Saturday's round. "I felt pretty groggy on the front nine just from the drugs that I had in my system."

He would start off slow, getting two bogeys on his first four holes, but began climbing up the leaderboard as the day went on, finishing with five birdies against one bogey on the back nine.

"I just tried to get it in, really. I just wanted to get it in," said Day, who has had a history of dizziness, having had to withdraw from tournaments a couple of times before.

"When anybody's sick, they always say to be scared of the sick golfer," Day's playing partner Kevin Kisner said after Saturday's round. "He showed that today. It always seems to work out that way for some reason."

Last May, Day withdrew from the AT&T Byron Nelson, after complaining of dizziness during practice round. And in August of last year, he also withdrew from the WGC-Bridgestone Invitational due to vertigo-like symptoms.