Kevin, external: Completely forgot the US Open was on with all the wall-to-wall World Cup coverage!

Rory McIlroy has advised leader Martin Kaymer to keep the pedal to the metal. McIlroy knows only too well how it feels to throw away a tournament from a seemingly impregnable position after his infamous meltdown while four ahead at Augusta in 2011.

Image source, Getty Images

"On a golf course like this, you can't go out trying to protect anything. You've just got to keep the foot to the floor and just keep it going," says McIlroy.

"I learned at the Masters, the previous major before Congressional (where he won the US Open), if you get too defensive, it's detrimental."

Defending champion Justin Rose has just started his third round and will have to come from 11 shots back if he is to become the first man to win back-to-back US Opens since Curtis Strange in 1988 and '89.

"On both rounds I've not got the score out of how I played," says Rose. "The way the golf course seems to be playing today means the wind coming from the north may dry things up a bit. That's what the chasing pack need, for the course to get firm and fiery.

"Martin seems unflappable but from my point of view it's about just getting more good scores on the course."

Pablo Larrazabal tweets:, external "Thinking about yesterday's back nine and I can't find an answer of it... US open conditions can kill a round in one second."

Larrazabal was nine over for his back nine in round two and finished nine over for the tournament.

American Cody Gribble has birdied the par five 10th to join the trio of Sergio Garcia, Shiv Kapur and Lucas Bjerregaard who are one under for the day. Faultless but unspectacular so far from Phil Mickelson as he opens with five straight pars, although he's in the sand on the sixth and on course for a bogey.

Paulo Brand, external: I fancy Henrik Stenson & Rory McIlroy to make Sunday's final 2 groups though Martin Kaymer's too strong to let this go

Image source, Getty Images

Those of you who were around when everything was in black and white might remember that even greats like Arnold Palmer can botch a humungous lead. The seven-time major winner was seven clear of Billy Casper (pictured) as he stepped onto the 10th tee in the final round at the Olympic Club, San Francisco, in the 1966 US Open.

But, yep, you've guessed it, he creaked and crumbled and his collapse led to an 18-hole play-off. Palmer led by two at the turn in the shoot-out but lost and would never win another major.

While everyone else are placing their chips on a Martin Kaymer victory, merely hanging around to watch the spinning wheel stop out of politeness, the German himself does not believe the trophy is his yet.

"It's not a done deal," said Kaymer, who holed the winning putt for Europe in the Ryder Cup at Medinah in 2012. "You don't approach Saturday and Sunday in a relaxed way.

"It's never a time when you can relax, unless it's Sunday afternoon and you are raising the trophy. There's never a time you can take it easy, you have to set your own goals and keep playing well."

Lee Westwood, who missed the cut, tweets:, external "If they make the course tough over the weekend Martin can't lose."

A quick update for you. Thirty-five players are on the course an it seems to be an afternoon of toil for many of them because only three players are under par for the day. They are Sergio Garcia (-1), Shiv Kapur (-1) and Lucas Bjerregaard (-1).

The consensus is clear. This is Martin Kaymer's tournament to lose.

"As Martin Kaymer was reducing Pinehurst to sawdust yesterday, it was difficult to tell which were falling quicker - records or the jaws of his rivals," writes James Corrigan in the Daily Telegraph., external "At 10 under, with the lowest US Open halfway total already in his grasp, this is surely the German's major to lose."

The Guardian's Ewan Murray says:, external "Kaymer's grip on the 114th US Open has tightened to the extent that this is now his tournament to lose. Those in pursuit of the former world No1 need binoculars. And snookers."

And James Nursey writes in the Daily Mirror: , external"Martin Kaymer has a golden opportunity to clinch the US Open title this weekend after his heroics continued at Pinehurst"

The question is: Now that history has been made, does that mean the rest of the field are history too? Will Martin Kaymer stumble and where is he likely to do so? And who from the chasing pack is the more likely to hunt him down?

You can tweet your thoughts using the hashtag #bbcgolf, text 81111 or post your thoughts on BBC Sport's Facebook page.

Here are some number-crunching statistics for you. Martin Kaymer, in imperious form as we know, reached halfway in 130 shots to eclipse Rory McIlroy's record mark of 131 when he won the US Open at Congressional in 2011.

Image source, Getty Images

And there's more. He also equalled the best 36-hole mark at any major championship, set by Nick Faldo in the 1992 Open at Muirfield and Snedeker at Royal Lytham in 2012.

Iain Carter
BBC golf correspondent at Pinehurst

"By becoming the first player to card the lowest round on consecutive days, Kaymer has confirmed his domination of this US Open. It has been as though he has been playing a different course to the rest. His opening 36 holes have been very special and the chasing pack are wondering how it is possible to go so low.

"However, Kaymer is right to acknowledge it is far from over. Pinehurst remains far too treacherous for him to ease off the gas or to change approach to defend his lead over the weekend."

The US Open is in Martin Kaymer's hands says Graeme McDowell, who is 12 shots adrift of the German.

"He has had an incredible two rounds of golf," says McDowell. "He's got a big task on his hand these next 36 holes but it's even more massive for the rest of the field. For me, the US Open is in his hands but if he plays how he can, no-one can touch him.

"I won't be focusing on him. If we're playing for second place, then second place is a pretty nice prize here."

Danno, external: Kaymer will see it as his title already and after a poor first round, Adam Scott will show why he is ranked number 1

Rory McIlroy, on one under par, says he will "need something pretty special" to hunt down Martin Kaymer, but the Northern Irishman has been spending time with 18-time major winner Jack Nicklaus.

"I feel like I've developed a great relationships with him over the past five years," says McIlroy. "I met him last week in his office and talked not just about golf but life and how you balance things. He's been a great help and to be able to lean on him for help when I need to it's huge."

Phil Mickelson sees his way out of trouble, getting the iron out on the edge of the green and he will probably escape with a par. Actually, he did negotiate the second hole in four shots but there have been no pictures of it yet.

Having mentioned that Phil Mickelson is out on the course, I suppose I had better quickly list some other tee times (in British Summer Time).

17: 40 Graeme McDowell & Lucas Bjerregaard

18:13 Aaron Baddeley & Justin Rose

18:24 Jason Day & Marcel Siem

18:46 Steve Stricker & Rickie Fowler

19:52 Keegan Bradley & Brendon De Jonge

20:03 Dustin Johnson & Brooks Koepka

20:14 Brandt Snedeker & Kevin Na

20:25 Brendon Todd & Martin Kaymer

Phil Mickelson has just started his round alongside Webb Simpson. Lefty was three over at the halfway stage after a 70 and 73 and the six-time runner-up will have to wait at least another year to complete a career Grand Slam. A steady start for the American who opens with a par four on the first.