Martin Kaymer gave Rory McIlroy a glimpse of what his future could be when he completed a remarkable, wire-to-wire, eight-shot US Open win at Pinehurst No 2.

The 29-year old German (aided by his caddie Craig Connelly) gave a masterclass in course management, closing with a one under 69 to win on 271 from Eric Compton (72) and Rickie Fowler (72).

McIlroy tied for 23rd, 15 strokes behind the German on six over par after weekend rounds of 74 and 73.

And he had no problem admitting that his course management needs attention if he is to win a major on a hard, fast running course such as Pinehurst No 2. 

"I'm wondering how he did it, yeah. It's tough. I think I've made a total of nine birdies this week. I don't see anymore out there. It's tough. Obviously, if you limit the mistakes, you might end up a couple under par for the week, because you're always going to make a few mistakes. But to do what he's doing is -- I think it's nearly more impressive than what I did at Congressional."

Asked what he had learned, McIlroy said: "Course management. Strategy-wise, [I] just need to be a little bit better and a little -- I'm looking forward to coming back and playing a US Open in tough conditions again and firm conditions, because that's the only way that you're going to learn how to play it is experience."

An outward nine of 40 on Saturday ended McIlroy's remote chances at Pinehurst but he does not believe those poor runs are an insurmountable problem

"It's just a matter of, just putting your ball in the right places here and not letting one hole turn into two, turn into three, that sort of thing," he said

Graeme McDowell tied for 28th with Phil Mickelson on seven over after a battling 70 and admitted he was motivated to keep going by his need to climb the rankings both in terms of the FedEx Cup and the Ryder Cup.

"Those last 27 holes there, I tried to dig deep and put some dollars on the board," McDowell said. "I've got to keep playing hard this summer."

He made eight birdies and an eagle over the four rounds as well as 15 bogeys and one double.

He tweeted an Instagram picture as he headed for Fota Island and this week's Irish Open that summed up his week.