Dustin Johnson at the top of the leaderboard in a major. Who’d have thought it?

Johnson did as he habitually does in the opening exchanges, blew the bloody doors off a challenging golf course, posting a 64 to claim the clubhouse lead at the PGA Championship on six under par.

Let’s hope he has read the rule book this time and elects not to ground a club in a bunker. The one that cost him so dearly on the final hole five years ago when he led by one is now buried beneath corporate seating.

With more than a thousand more where that came from at Whistling Straits Johnson must keep his wits about him, and more importantly his nerve as the week progresses. You will need no reminding that he had a putt to win from 20 feet at the US Open two months ago and last month at the Open Championship at St Andrews he led at half way before falling apart.

“I really felt like I had may ball under control a lot like the US Open. We’ll just have to see what happens. It’s only the first round. We’ve still got a lot of golf to play. All I’m looking for is a chance to get it done on Sunday,” he said.

Jason Day and JB Holmes were among the group two further back on four under. Justin Rose recovered from two early bogeys to stand three under after a 67. “It's a platform on which I can build now for the rest of the week. You can never win it on Thursday, you can only lose it. That's obviously a good job done today,” Rose said.

It was another disappointing morning for Tiger Woods, who started neatly enough without holding a putt. When the sun came out and breeze stiffened on his back nine he laboured, carding three bogeys in four holes en route to 75.

“I hit it great today, but I made nothing, probably one of the worst putting rounds I’ve had in a very long time, so that’s about it,” Woods said.