• by David Goetzl  @dgoetzl, March 27, 2006

Normal also-rans NBC and ABC again capitalized on the weak--although improved--NCAA Basketball Championship on CBS to grab the top two spots on Thursday night.

NBC won the night in adults 18-to-49--the network is a distant second for the season--and second-place finisher ABC had a bright spot at 9 p.m. as new reality show "American Inventor" won the time slot in the key demo for the second week in a row.

CBS, the dominant season leader, finished third for the second straight week because of the niche-appeal NCAA tournament. The tournament, which scores well among young men, did show improvement from a week ago as adult 18-to-49 rankings climbed 11 percent and the tournament moved into the Sweet 16.

Now that CBS has emerged as a power for the night, the two Thursday nights it devotes each year to the NCAA have become a double-edged sword. On the plus side, it can serve to expose typically non-CBS viewers--primarily young males--to the network, where they may view promos for appealing shows like new hit drama "The Unit" or "Two and a Half Men," and decide to tune in later. However, deviating from its wining "Survivor"-"CSI:"-"Without a Trace" troika considerably slows the network's momentum on the night where advertisers pay a premium for pre-weekend exposure.

This year, it also opened the door for ABC to successfully launch the Simon Cowell-produced "American Inventor." On March 16, the show propelled ABC to its first Thursday win in the 18-to-49 demo by one measure since 1991. "Inventor," however, slipped by 6 percent last week, raising questions whether it has staying power or is simply a beneficiary of savvy scheduling. Next week will be telling when it faces off against a new "CSI:."

A disappointment for ABC on Thursday was a special post-Katrina episode of its Sunday top-10 show "Extreme Makeover: Home Edition," which finished second in the 8 p.m. hour.