Jason Day has imploded during the third round of the US PGA Championship, surrendering a solid chance at chalking up a second career major.

After starting day three of the year’s final major just two shots off the pace, the Australian world No.7 crashed out of contention spectacularly with a six-over-par 77 at Quail Hollow in North Carolina.

The 2015 US PGA Championship winner plummeted to a share of 16th at even-par, seven shots back of leader Kevin Kisner.

The American Kisner also battled to a rollercoaster 72 but at seven-under the card the South Carolina native clung to a one-shot lead over world number three Hideki Matsuyama (73) and Chris Stroud (71).

Justin Thomas (69) and 2010 British Open winner Louis Oosthuizen (71) share fourth a shot back at five-under.

Playing in Saturday’s final group with Kisner and Matsuyama, Day’s nightmare round was epitomised by a bizarre decision on the par-four 18th hole to go for the green with his approach after finding trouble from the tee.

Photo: Day made some questionable decisions during his round. (Reuters: Rob Schumacher)

The 29-year-old Australian hit his second shot into a shrub and had to take a penalty drop en route to a crippling quadruple-bogey eight.

It soured a brief comeback during which Day bagged three consecutive birdies from the par-four 14th which kept him in the hunt despite a poor opening 13 holes.

Day gave back a shot on the front nine at Quail Hollow before a nightmare two holes saw the Queenslander double-bogey the par-four 12th and bogey the par-three 13th.

Fellow Australians Adam Scott and Marc Leishman are well off the pace after three rounds.

Leishman carded a 71 to remain at four-over while world No.17 Scott fell further behind with a 74 to sink to eight-over for the championship.

-AAP