Imagine what this news is going to do to Simon Cowell's already swelled head.

According to preliminary Nielsen ratings, Wednesday's 90-minute episode of FOX TV's "American Idol" averaged a 12.6 rating/30 share among adults 18-49, which exceeds the show's previous series-high (12.4/30), established last week.

Translated, that means that, overall, this week's edition of "Idol" averaged 26.01 million viewers, only a hair below its opening-night audience of nearly 27 million last Tuesday.

As analyzed by Variety, that is the biggest score in the key 18-49 demographic for any FOX series since an episode of "The X-Files" in November 1997. As such, the trade paper deduces -- given that FOX also has a two-hour "Joe Millionaire" finale coming up in two weeks, just in time for the February sweeps -- the network is poised to corner the market in adults 18-49. It would represent a coup for FOX, which placed a distant fourth in the November sweeps.

Meanwhile, in its second -- and final -- face-off, "Idol," with its 26 million viewers, widened its lead over ABC's "The Bachelorette." Though the ABC program pulled in a respectable 14 million viewers, "Idol" took the lion's share of the advertiser-coveted younger audience.

"Bachelorette" Trista Rehn -- like "Joe Millionaire," down to three suitors -- will make her final selection Feb. 19.