World No. 1 Jason Day started hot in the third round of the British Open on Saturday, four-under par through nine holes, but he finished with an even-par 71 at Royal Troon in Ayrshire, Scotland and was tied for 30th.
Meanwhile, Jordan Spieth's struggles continued, as he shot his 10th consecutive round in a major without going under par. Spieth shot a one-over 72 early Saturday and is five over through 54 holes, and was tied for 58th with Bubba Watson and Jim Furyk.
"I'm hitting the ball great, I'm just really struggling on the greens this week," said Spieth. "I'm struggling reading them and then because of that I have a tough time hitting a nice, solid putt on a line and being confident about it. I've missed four putts maybe inside of five feet today - a couple from two feet."
Masters champion Danny Willett encountered trouble as well, shooting a three-over 74. He is seven over for the tournament.
Brandt Snedeker and Haydn Porteous put together some of the best scores of the morning, each shooting three-under 68s. Snedeker and Porteous stand at one over.
Rickie Fowler's round got off to a solid start with two birdies in six holes.
Rory McIlroy dropped to one under for the tournament after six holes played, and U.S. Open champ Dustin Johnson was two under through three holes.
Mickelson, at ten under, will tee off at 10:20 a.m. EST with Henrik Stenson (nine under).
[Click here for the entire leader board from Royal Troon.] (http://www.golfdigest.com/story/british-open-leader-board)