World number one Jason Day birdied two of the last three holes to seize a one-stroke lead over David Lingmerth after the second round of the World Golf Championships Bridgestone Invitational.

Australian Day, preparing for the British Open in two weeks and readying to defend his first major title in the PGA Championship at the end of the month, fired a one-under par 69 to stand on four-under 136 after 54 holes at Firestone Country Club in Akron, Ohio.

"One of those days where you really just had to stay patient," Day said. "It's really difficult to make birdies out there. I was able to get a couple coming in. The greens are starting to get firm and fast.

"I'm just very pleased to shoot under par."
Day's total matched the highest leading score ever at the halfway mark of the event and the scoring average of 72.2 is the second-highest in tournament history.

Sweden's David Lingmerth was second on 137 with Argentina's Emiliano Grillo and Americans Scott Piercy and William McGirt on 138 and Australia's Adam Scott joining world number two Jordan Spieth and fellow Americans Kevin Kisner and Justin Thomas on 139.

Day seeks his 11th US PGA crown and fourth title of the year after the Arnold Palmer Invitational, WGC Match Play Championship and the Players Championship. The Aussie, who began the round three strokes adrift, could match Tiger Woods as the only players to win back-to-back WGC titles.

Day sank a 25-foot birdie putt at the par-4 third hole and made 12-foot par saves at seven and eight.

"Holing those keeps momentum going, keeps you patient," Day said. "Once that happened, I just said I need to stay patient."
Day opened the back nine with a bogey, three-putting from 16 feet. But he took the lead late with a five-foot birdie putt at the par-5 16th and dropped a 16-footer for birdie from the fringe of the 17th green for a two-stroke edge.

A stumble on 18 trimmed the lead to a single shot, Day missing the green with his approach and errant on a six-foot par putt.

"The short game has definitely saved me the last two days," Day said. "Hopefully my long game can pick it up the last two days and I can make it a lot more stress-free on myself."

Lingmerth made an astonishing putting run on the front nine, sinking birdie putts of 22 feet at the par-5 second, 60 feet at the par-3 fifth, 18 feet at the par-4 eighth and 26 feet at the par-4 ninth. 

But he found a bunker at 11 and missed a 15-foot par putt, answered with a 24-foot birdie putt at 13 only to falter at the finish, finding rough off the tee and coming up short of the green on his approach on the way to a bogey at 18.

"I was scrambling really good and a made a couple nice putts. I scored pretty well. Overall it was a nice day," Lingmerth said. "I want to sort the swing out. It's not far off but I want to strike it a little better over the weekend."

Source; ADP