NEW YORK – After blitzing Rafael Nadal in straight sets in the U.S. Open semifinals, Juan Martin del Potro called it the “best moment of my life.”So how did he feel a day later after pulling off the seemingly impossible and knocking off five-time defending Open champion Roger Federer in an epic five-set final? “Much better,” No. 6 del Potro said after his stunning 3-6,7-6 (5), 4-6, 7-6 (4), 6-2 victory ended No. 1 Federer’s five-year run and 40-match winning streak in Flushing Meadows. Read the full story here. Serena offers apology, wins women’s doubles with Venus.