Daniel Summerhays is on target to claim his first PGA Tour title as he takes a three-shot lead into the final round at the Memorial Tournament after carding 68 in Ohio on Saturday, while Ireland's Shane Lowry is eyeing a top-10 finish after another good day at the office.

Summerhays, who finished third in last year's PGA Championship, trailed midway leader Jason Dufner by five shots overnight but five birdies - and a bogey on the 13th - saw the 33-year-old from Utah move into the outright lead on 13 under par ahead of 2013 winner Matt Kuchar.

Kuchar moved up to second thanks to a round of 67 that included six birdies and one bogey for the joint-second lowest score of the day on 10 under. Compatriot James Hahn won that prize by two shots as his 65 - which included an impressive 10 birdies and three bogeys - moved into a share of 14th on five under par.

Dufner dropped down to a three-way tie for third after a poor round of 77 which six bogeys and a double bogey on the 11th hole, which undid the good work of birdies on the seventh, 15th and 17th.

The former US PGA champion, seeking a fifth PGA Tour title, sits alongside Bubba Watson (68) and Justin Thomas (69).

Rickie Fowler (72) and Jamie Lovemark (70) are a shot further back in joint sixth, with Kevin Streelman, Kevin Kisner and Jordan Spieth completing the top 10 - the trio in a tie for eighth on seven under.

Lowry is the highest-placed European on the leaderboard following a third-round 70, including six birdies and four bogeys. He moves into a three-way tie for 11th on six under.

Padraig Harrington shot a level par 72 that included an eagle at the par-five 15th to lie in a tie for 38th at two under par.

"I think theres only a couple of guys who have not gone through the learning curve," said Summerhays, who finished a quiet third at last years PGA Championship.

"My games really solid right now. Ive had two months of playing really good golf and not getting any results.

"I drove it really well. I had so many good looks at birdie, so many putts were just so close. Given the circumstances, the Memorial tournament, performing under the gun, it was really fun."