World number one Jason Day, four-time major champion Rory McIlroy and five-time major winner Phil Mickelson were poised to make morning charges at Baltusrol as the 98th PGA Championship began Thursday.

Sunny skies greeted the early starters from the field of 156, the strongest line-up of talent in any event based on world rankings since their 1986 creation.

The 7,428-yard, par-70 layout features only two par-5 holes, those at 17 and 18 to ensure drama and eagle chances to the end.

Defending champion Day has struggled in the run-up to the year's final major tournament with only a Wednesday practice round, an illness and a hospital trip after his wife Ellie suffered an allergic reaction after the Champions Dinner on Tuesday.

"I really don't look at it as a title defense," Day said after having taken his first major title last year at Whistling Straits.

"I really look at it as I need to come back in, try and execute a game plan and try and win the tournament. I won it last year. That was fantastic and I need to focus on what I need to do this year to win the Wanamaker Trophy again."

McIlroy, playing alongside Day, won the Irish Open and has nine other top-10 showings in US and European Tour events this year, including a share of fifth at the British Open two weeks ago.

"I feel like my game is in good shape," McIlroy said.

"Everything is straight out in front of you. There's no real hidden secrets to it. That's what really let's me excel. I feel like I can play my game in PGA Championships. I can hit driver off the tee and from there, if I drive it well, I feel like I have a big advantage."

Mickelson, who completes the trio teeing off at the 10th hole 90 minutes after the opening shot, won the 2005 PGA at Baltusrol and comes in off his 11th runner-up showing in a major, having lost a duel with Sweden's Henrik Stenson at the British Open.

At 46, the US left-hander would be the fourth-oldest major winner if he claims the title. And it does not hurt that "Lefty" is a fan favorite in the metro New York area.

"It not only makes it fun to play but it also keeps my energy level up throughout the round when I have a tendency to make a mistake or two," Mickelson said. "It helps me overcome some of those mistakes. I'm very appreciative for the way people here have treated me."

Other early starters include past PGA winners Vijay Singh, John Daly and Padraig Harrington, South African four-time major winner Ernie Els, Americans Rickie Fowler and Zach Johnson, Japan's Hideki Matsuyama and Australian Adam Scott.

- Major winners start late -

Stenson, US Open winner Dustin Johnson of the United States and Masters winner Danny Willett -- this year's major winners -- tee off in the afternoon feature group off the first tee, with only three final trios behind them.

Just in front of them are England's Justin Rose, American Patrick Reed and South African Louis Oosthuizen.

And the trio teeing off ahead of that offers two-time Masters champion Bubba Watson, another American in two-time major winner Jordan Spieth and Spain's Sergio Garcia, trying to win his first major title in his 73rd try and 70th consecutive major start dating to the 1999 British Open.

"The only thing I can do is just keep giving myself chances and just wait for it. Hopefully it will happen," Garcia said.

"If it doesn't happen, it's not going to change my life. I'm not going to go in a cave and stay there until I die because I didn't win a major or anything like that. It's not that serious.

"I'm not going to lie. It would be nice to get at least one. But it's not the end of the world."

Source: AFP