Joost Luiten claimed an early advantage at golf's final Major of the year as Rory McIlroy took a share of the clubhouse lead with a superb five under par 67 at Kiawah Island.
The thunderstorms of earlier in the week gave way to dry and boiling hot conditions for the start of the US PGA Championship and players took advantage on the course made famous by the "War on the Shore" Ryder Cup in 1991.
McIlroy's round put him in a share of second place one behind Dutch debutant Luiten, who after an eagle and four birdies still had six holes to play.
In last month's Open Championship at Royal Lytham McIlroy's hopes of a second Major title nosedived after he rebounded off a teenager's head out of bounds late on the first day.
On this occasion he hit a lady on the hip after badly pulling his tee shot to the dangerous short 17th - his eighth - but it came back into a nice lie in the sand only 25 feet from the flag.
From there the 23 year old Northern Irishman, already three under for the day, splashed out to six feet, saved his par and brought a cheer from the gallery by running back to give the fan the ball.
McIlroy had opened with a 12 foot birdie putt, converted a ten foot chance on the short 14th and then chipped to six feet at the long 16th - a hole which saw then playing partner Jim Furyk, three under at the time, needing three attempts to putt up a bank right of the green and take a double bogey seven.
Come the front nine McIlroy picked up further strokes at the long second and 480 yard sixth and kept a bogey off his card to be in the clubhouse alongside big-hitting American Gary Woodland.
Former amateur star Luiten is playing his first Major in America this week and it was a dream start, three birdies in five holes being followed by a 25 foot putt for eagle at the 581 yard 16th.
Tiger Woods was another early starter and after two birdies and two bogeys in the first six holes he had a hat-trick of birdies around the turn, but then dropped another stroke at the 458 yard fourth to stand two under.
World Number One Luke Donald, Graeme McDowell, Padraig Harrington and Justin Rose were among the later starters hoping the wind would not get up too much.
Pettersson went to six under on the long 16th, but Luiten was an incredible eight under after hitting his approach to a foot on the fourth and a tee shot to six feet at the next.
He had a chance to equal the Major record of 63 - or even break it - but bogeyed the next.
McIlroy said: "It's becoming a habit hitting people at Majors, so I will try not to do that again.
"I think that's my first bogey-free round in a while and it was a great way to start.
"I'm pretty comfortable on the course and only played nine holes on Monday and nine on Tuesday - I didn't feel I needed to play more.
"I'm expecting this to be the best day of the week (weather-wise), but it's hot and you just try to stay hydrated."
