( CNN ) -- Martin Kaymer stretched his lead at the top of the U.S. Open leaderboard with a second successive round of 65 at Pinehurst No . 2 Friday . The German 's combined score of 130 over two days is the lowest 36-hole score in the history of the U.S. Open . The record was previously held by Northern Ireland 's Rory McIlroy who carded 131 ( 65 and 66 ) over the first two rounds as he went on to win the 2011 U.S. Open at the Congressional Country Club 's Blue Course in Bethesda , Maryland . `` I played very well , '' former world No . 1 Kaymer told the U.S. Open website upon reaching the clubhouse . `` I had some good rounds in the past as well . But yesterday and today , especially today , the way I worked my way around the course ... I hit some smart shots . `` I did n't play too aggressive and when I had a good number , I went for the flag and I did n't make many mistakes on the greens . I did n't three putt , I made a lot of good putts today and yesterday . '' At 10 under par , Kaymer was six shots clear of second-placed American Todd Brendon going into the weekend , as he seeks his second major title . Brandt Snedeker and Kevin Na were a shot behind compatriot Brendon at three-under-par while a group of five players including Dustin Johnson and Henrik Stenson were tied for fifth on two under . Despite his considerable advantage Kaymer -- who won the U.S. PGA Championship in 2010 and picked up the Players Championship at Sawgrass last month -- refused to look beyond Saturday , where he hopes to maintain his lead . `` It 's not a done deal , '' the world No . 28 said . `` The last three , four holes , I got a little bit tired . I did n't swing as good as the first 14 holes . '' Kaymer 's wariness is perhaps understandable given a poor spell of form suffered over the last 18 months . But current world No . 1 Adam Scott was less convinced by talk of Kaymer 's perceived slow finish . `` If he does it for two more days , then we 're all playing for second spot , '' the Australian told reporters . Scott was tied for 14th position at level-par but still holds out a slim chance of catching the runaway leader . `` We all know that U.S . Opens get very difficult and if I can just somehow put together two really good rounds , maybe slowly but surely I 'll creep my way up towards Martin . '' Elsewhere on the course , two bogeys on the final three holes made for a disappointing finish for in-form young American Jordan Spieth , who ended the day at one-under-par , nine off the pace . The 20-year-old , who tied for second at the Masters in April , was equal 10th alongside McIlroy ( 68 ) , world No . 5 Matt Kuchar ( 70 ) and fellow American Chris Kirk ( 68 ) . Meanwhile , reigning U.S. Open champion Justin Rose shot a carded a 69 to finish the day at one-over-par after a difficult 72 on Thursday . Six-time runner-up Phil Mickelson was tied for 33rd after a 70 . Masters champion Bubba Watson shot the same score , but missed the cut by one stroke following his opening 76 . Former world No . 1 Luke Donald will also miss the weekend rounds along with major champions Charl Schwartzel , Angel Cabrera , Geoff Ogilvy , Darren Clarke and Lucas Glover .
Martin Fischer scores second 65 in two years at U.S. Open . German makes lowest break total in tournament 's history . Former World No . 1 holds six - shot lead over second - placed Todd Brendon .