The NFL season’s kick-off beat all comers Thursday night, with the New York Giants’ victory over the Washington Redskins scoring about 13.6 million viewers, according to Nielsen’s overnight ratings. The defending Super Bowl champions’ triumph handed NBC an easy win in total viewers and young adults for the otherwise sleepy early-September evening. Closest competitor Big Brother on CBS garnered about 6.5 million viewers; two hours of Fox’s Kitchen Nightmares cooked up 5.5 million; and a repeat performance of this week’s 90210 premiere attracted another 2.1 million gawkers.