SportsHorschel, Donald lead US Open as Tiger, McIlroy hang toughAFPJune 15, 2013June 15, 2013 by AFPJune 15, 2013June 15, 2013 ARDMORE, Pennsylvania: England’s Luke Donald and unlikely American Billy Horschel were second-round US Open clubhouse leaders on Friday while Tiger Woods and Rory McIlroy grinded...