Jason Day leads WGC-Bridgestone at Firestone

The Australian fired a one-under 69 in Akron, Ohio, on Friday to move to four under.

Day is a shot clear of Swede David Lingmerth and two ahead of overnight leader William McGirt, Emiliano Grillo and Scott Piercy.

One-time major winner Day mixed three birdies with two bogeys, including a blemish at the last.

He made birdies on 16 and 17, the latter from 16 feet, before narrowly missing his attempted par save on the last.

Nonetheless, Day will take a lead into the weekend after McGirt in particular struggled.

The American carded a four-over 74, battling on the back nine.

McGirt was even par through his first nine holes, but had a double bogey and two bogeys to finish.

His day was summed up on the last, where he found the bunker to produce a six and slip back into a tie for third.

Lingmerth was far more impressive with a 67, while Grillo (71) and Piercy (69) were solid.

Jordan Spieth and Adam Scott are among those lurking just behind.

World number two Spieth had a 71 to be at one under alongside Scott (68), Justin Thomas (69) and Kevin Kisner (70).

Rickie Fowler is also in contention despite a 73 leaving him at one over.

Defending champion Shane Lowry, however, continued to struggle and sits at eight over.