The two-hour finale of reality phenomenon “Joe Millionaire” delivered the best ratings for a night of entertainment programming in Fox’s history, according to preliminary nationals from Nielsen.

From 8 to 10, “Joe” averaged a stunning 17.6 rating/36 share in adults 18-49 and 34.6 million viewers overall – making it the top-rated score in both categories for an episode of any series this season and the best demo score for the finale of an unscripted skein since the first “Survivor” in August 2000.

By its final half-hour, “Joe” climbed to a 21.8/42 in adults 18-49, topping its combined ABC-CBS-NBC competition by 19 shares.

In the 10 o’clock hour, the second half of NBC’s “Dateline: Michael Jackson Unmasked” drew a strong 7.7/17 in adults 18-49, topping CBS drama “CSI: Miami” (6.9/16), which pulled ahead in total viewers (18.1 million). For its two hours, “Dateline” netted a 5.8/12 in adults 18-49 – NBC’s strongest 9-11 p.m. score on a Monday since last April.

Head-to-head, NBC’s “Dateline” spec on Jacko topped ABC’s repeat of the Granada documentary (6.2/13 vs. 3.5/7 in adults 18-49).

Preliminary 18-49 averages for the night: Fox, 17.6/36; NBC, 5.7/12; CBS, 5.2/11; ABC, 3.4/7.

In total viewers: Fox, 34.6 million; CBS, 15.6 million; NBC, 13.5 million; ABC, 9.7 million.