A double-bogey on the 15th hole was the only significant blight on Day’s card, which included eight birdies and an eagle, as he stepped up his bid for a first major title.

Day mixed three birdies with two bogeys over the first five holes before picking up shots at nine and 10 and holing a 12-foot putt for eagle at the 11th.

Further birdies at 13 and 14 followed, and despite posting a six at the par-four 15th, Day responded by sinking a 25-foot putt for birdie at 17.

"Overall I'm very pleased with the way I came back," said Day.

"The putter was rolling today, which was great."

The United States’s Jordan Spieth is Day’s closest challenger, posting a superb 65 following a run of six birdies over the last eight holes to give him an extremely good chance of adding to the Masters and US Open titles he won earlier this year and becoming only the third player in history to win three majors in a calendar year.

Day’s compatriot Matt Jones, the halfway leader after the second round was belatedly completed in the morning, held a three-shot advantage following birdies at the first and sixth before bogeying nine after driving into the hospitality tent.

He fought back with birdies at 11 and 14 but bogeys at 15 and 16 and a double-bogey at 17 left him at 10 under, tied with the US’s Tony Finau.

England’s Justin Rose bogeyed the 18th to end the day on 12 under and shares third position with South Africa's Branden Grace, who shot a day’s-best 64.

Former champion Martin Kaymer of Germany moved into contention at 11 under with a 65, while world number one Rory McIlroy’s 68 took him to six under.

American Dustin Johnson and India’s Anirban Lahiri are both six shots off the pace at nine under.

Fourteen-time major winner Tiger Woods finished the second round at four over par as he missed the cut for a third successive major.


Related stories
August 2015: Australians Day and Jones share day two lead at US PGA Championship as storm halts play
August 2015: Johnson top of leader board again after US PGA Championship opening round
July 2015: Zach Johnson wins second major with play-off victory at The Open
July 2015: Amateur shares Open lead at St Andrews but Spieth poised to strike for historic third consecutive major victory
July 2015: Johnson preserves one-shot advantage on weather-affected day at The Open