BETHESDA (AFP) - From ranking leaders Luke Donald and Lee Westwood of England to the most unheralded qualifiers, golfers get a unique thrill from the mental test and physical challenge of a US Open. "We all come here excited to see what lies in front of us," said defending champion Graeme McDowell. "The rest of the major championships have upped their game, but there's something special about the US Open." The 111th edition of what many players call golf's toughest test begins Thursday (today) at Congressional Country Club, with Donald and Westwood seeking their first major titles as slight favorites in a wide open field of contenders.