On a warm afternoon at Pinehurst No. 2, Martin Kaymer rose to the top of the leader board with a 5-under 65, the lowest opening round in a U.S. Open since 2009. Learn more with our live updates. Kaymer, the 2010 PGA Championship and reigning Players Championship winner, posted the first 65 in nine U.S. Open rounds at Pinehurst No. 2. No one had shot that score in the 1999 or 2005 U.S. Opens. The German has had just one top-10 finish in 13 worldwide starts in 2014, and that was his victory at TPC Sawgrass. Kaymer has one top-10 finish in six previous U.S. Open starts. He shared eighth in 2010. He also led after an opening 63 at the Players Championship earlier this year, but before that, his last first-round lead was in 2009 on the European Tour. Graeme McDowell and Kevin Na shared the lead after morning wave ended. They opened with 2-under 68s, and were joined in second place by Brendon de Jonge and Fran Quinn, who played in the afternoon wave.