Taking advantage of the usual relatively slow start of CBS's coverage of March Madness, ABC debuted its new American Inventor on Thursday and came away with its best ratings numbers for the night since the height of Who Wants to Be a Millionaire hysteria six years ago, winning top honors for the night with an 8.4/14 in the 8:00 p.m. hour and a 9.2/15 at 9:00 p.m., giving ABC an overall win in primetime with an average 7.8/13. Daily Variety observed that the network also won the night among the key 18-49-year-old viewers -- the first time it had done so on a Thursday night with series programming in at least 15 years. CBS, the usual Thursday-night winner, slipped to second place with a 7.3/12. NBC finished third with a 7.0/11, while Fox (without a Thursday-night American Idol in its lineup for the first time in four weeks) fell far behind with a 3.5/6. Ratings for the NCAA basketball tournament remained about par with last year on CBS from Thursday through Sunday, jumping to first place on Saturday, usually the lowest-rated night of the week, and during the 7:00 p.m. hour on Sunday, where an overrun pushed CBS's regular lineup into a later hour.