The week before Memorial Day is typically a schizophrenic one when it comes to television viewing, and that was indeed the case this year.

After the finales of “American Idol,” “Dancing With the Stars” and “Two and a Half Men” scored gaudy numbers in the first half of the week, the air came out of the broadcasters’ balloon as the holiday neared.

Sure, Fox did pretty well with its season preem of summer skein “So You Think You Can Dance” on Thursday, but there were few fireworks anywhere else. That same night saw mild scores for the season finales of a pair of shows — ABC’s “Ugly Betty” and NBC’s “Southland” — that have been booted to Friday for next season.

And on Sunday, ABC’s two-part movie “Diamonds” got off to a rough start, drawing a little over 4 million viewers and losing auds with each half-hour.

The NBA playoffs were the exception to the late-week swoon as action heated up in the best-of-seven conference finals. Six of the week’s top 20 programs were pro basketball contests on TNT, ESPN and ABC.

Overall, according to “live plus same-day” Nielsen averages, Fox cruised to victory for the week in adults 18-49 with a 3.6 rating/12 share in adults 18-49. ABC and CBS tied for second (2.1/7), followed by Univision and TNT (1.3/4) and sixth-place NBC (1.2/4).

Fox also led in both adults 25-54 (4.2/12) and persons 12-34 (2.8/11) as well as total viewers (10.2 million to 8.9 million for runner-up CBS).

Wednesday’s eighth-season finale of Fox’s “American Idol” was the dominant performer for the week (10.0 rating/28 share in adults 18-49, 28.84 million viewers overall) — even though it was down 12% in the demo and 9% in overall audience vs. last year. The previous night’s performance seg was a solid No. 2 for the frame (8.6/25 in 18-49, 23.82m).

For the season, the Tuesday and Wednesday editions of “American Idol” claimed the top two spots in the program rankings for a sixth straight year in adults 18-49 and for a fourth straight year in total viewers — unprecedented achievements.

Also for Fox, the special preview of new fall series “Glee” was sampled well behind “Idol” on Tuesday (3.9/10 in 18-49, 9.62m), and “So You Think You Can Dance” had all the right moves in its Thursday bow (3.4/11, 8.85m), on par with last year’s debut.

The week’s other entertainment series standouts were ABC’s “Dancing With the Stars” and CBS’ “Two and a Half Men,” with the former winning both Monday with its performance episode (4.4/13 in 18-49, 19.17m) and Tuesday with its two-hour finale (5.2/14, 20.31m).

“Two and a Half Men,” meanwhile, wrapped another season as TV’s top comedy by ruling its Monday timeslot (5.3/14 in 18-49, 16.18m). Also looking good was lead-out “Rules of Engagement” (4.4/11, 12.87m).

NBC had a very quiet week, shut out of the top 20 and led by Tuesday’s “Law and Order: SVU” (2.5/7, 6.93m). On Thursday, “Southland” wrapped its rookie season with nothing-special scores (1.9/6 in 18-49, 6.45m), although it did build on its lead-in and beat repeat dramas on ABC and CBS.

CW was paced by the season finale of “One Tree Hill” (1.3/3 in 18-49, 2.68m), which built on its lead-in from “Gossip Girl” (1.1/3, 2.23m).

Univision rode its hot telenovelas to a No. 3 finish for the week among adults 18-34 (1.3/5), tied with CBS and behind only Fox and ABC. For the season, the Spanish-language net finished with a record average aud of just under 4 million.

Basketball action claimed the top five spots among the week’s highest-rated cable programs, led by Sunday’s Game 3 of the Eastern Conference finals between Cleveland and Orlando on TNT (3.8/13 in 18-49, 8.97m) and Tuesday’s Game 1 of the Western Conference finals between Los Angeles and Denver on ESPN (3.6/10, 8.09m).

ABC also scored on Saturday with Game 3 in the West (3.5/13, 8.73m), which drew nearly three times the demo rating of any other program — broadcast or cable — on the night.