Martin Kaymer again cards 65

— -- PINEHURST, N.C. -- Before the U.S. Open began, Martin Kaymer didn't think a score of 65 was possible at Pinehurst No. 2.

Now he has two of them.

The soften-spoken German who broke American hearts when he sank the clinching putt at the 2012 Ryder Cup is now making a mockery of the U.S. Open. He added another round of 5-under-par 65 on Friday to reach the halfway point at 130, a tournament record.

Kaymer, who won the Players Championship last month and captured the 2010 PGA Championship, didn't make a bogey over the seemingly treacherous Pinehurst layout, where he led by eight strokes when he finished his round.

He became just the sixth person in the 114-year history of the U.S. Open to reach double digits under par during the championship and if his lead holds, it will eclipse the 36-hole record of six shots held by Rory McIlroy (2011) and Tiger Woods (2000).

McIlroy went on to win by eight shots at Congressional; Woods won by a record 15 at Pebble Beach.

After making six birdies and a bogey on Thursday, Kaymer added five more birdies Friday without a bogey.

And his statistics tell the story. Kaymer hit 12 of 14 fairways and missed just three greens. Each time he failed to find the green in regulation, he was in a bunker, and got it up and down for par each time. He has yet to have a three-putt green in the tournament and took 29 during the second round.

He is the first player in the history of all four major championships to open the tournament with two scores of 65.