PGA is Spieth's grand slam bogy

Jordan Spieth has conceded the last leg of a career grand slam is also the most difficult for him after he lost the chance to become the youngest to achieve the feat.

The 24-year-old Spieth had the chance to surpass Tiger Woods as the youngest player to win all four golf majors if he triumphed at the US PGA Championship.

But the two-time Australian Open champion fell out of contention on Saturday, his even par 71 leaving him 37th and 10 shots behind leader Kevin Kisner.

Woods was aged 24 years, seven months when he claimed the career slam at the 2000 British Open, while Spieth will be 25 during his next opportunity at the 2018 PGA.

"I didn't have it written in a diary from when I was young that I need to win a career Grand Slam as the youngest player ever - that wasn't the goal," said Spieth.

Spieth, who ranks 80th on the US PGA Tour for driving distance with an average tee shot of 294.2 yards, admitted the PGA Championship's tendency to favour big-hitters plighted him.

"If we look historically back on my career, I think I will play this tournament worse than the three majors just in the way that it's set up," Spieth said.

"I feel like my game truly suits the other three majors more than the PGA Championship."

World No.4 Rory McIlroy was another big name to crash out of contention, despite carrying pre-tournament favourite status courtesy of top-five finishes in his last two starts and a superb record at host Quail Hollow.

A third round of 73 left McIlroy at four-over and 11 shots off the pace.

McIlroy, who has won two PGA Championships in addition to US Open and British Open, also has the chance to complete the career grand slam at next year's Masters at Augusta.

"I'm looking forward to 2018," said McIlroy, whose 2017 season has been held back by 10 weeks sidelined with a rib injury as well as the sacking of long-time caddie JP Fitzgerald.