(Reuters) - Roberto Castro upstaged some of the biggest names in golf to take a one-shot lead at the rain-hit BMW Championship on Thursday with a seven-under-par 65, while defending champ Jason Day ended the day eight strokes back after a six bogey 73. FedEx Cup points leader Patrick Reed managed a respectable two-under 70 while Rory McIlroy, winner of the Deutsche Bank Championship on Monday, was three-under after 10 holes. Brian Harmon trails by one stroke, while major champions Dustin Johnson and Jason Dufner shot 67s and sit two back. More...