Diane Sawyer's interview with Rhianna, in which the pop singer spoke for the first time about being assaulted by her ex-boyfriend, Chris Brown, drew over 8.2 million viewers Friday night, making it the second-highest-rated show of the night, behind NBC's Law & Order, according to Nielsen Research -- a significant achievement for any primetime news program. The strong ratings were also regarded as a good sign that Sawyer will be able to compete effectively against NBC's Brian Williams when the two go head-to-head in the evening news wars early next year.