It’s toss-up Tuesday at the networks this sweep, as the week’s most wide-open night went to ABC this time in key demographics thanks to a pair of specials and the strongest “NYPD Blue” in three months.

It was also another great Tuesday for the WB’s lineup of “Gilmore Girls” and “Smallville” — which won the night among viewers under 35 — as well as MTV’s “The Osbournes.”

According to Nielsen, ABC edged NBC in adults 18-49 (4.3 vs. 4.1) for just its third Tuesday triumph in the demo this season (excluding sports). A week earlier, the conclusion of mini “Living With the Dead” vaulted CBS to only its third Tuesday 18-49 triumph in three seasons, while ABC ran fourth.

It’s ABC’s best Tuesday turnout (11.3 million viewers) and strongest demo deliveries since January.

Contributing to the Alphabet’s success was an 8 p.m. “Laverne & Shirley” reunion spec (10.71m, 3.6/10) that didn’t do huge numbers but did finish second in 18-49 to Fox’s comedy hour. It won in women 18-34, women 18-49 and adults 25-54.

An hour later, spec “Favorite Stars: Then & Now” ran a close second to NBC’s comedies in 18-49 (4.4/11) while winning in women 18-34 with the net’s best score in the Tuesday at 9 hour this season (4.8/13).

And at 10, “NYPD Blue,” with promos promising “one of the most powerful episodes in years,” led its hour in 18-49 (4.8/12) — its highest score since early February.

CBS scored its usual victory in total viewers but had a quiet night, falling to fourth in 18-49 and third in 25-54. “JAG” (13.21m, 3.0/9 in 18-49) and “Judging Amy” (12.65, 3.6/9) each won in total viewers but fell to firstrun season lows and were off about 15% from a year ago. “The Guardian” also won in viewers (12.05m).

NBC’s original episode of “Frasier” at 9 fell to its lowest 18-49 score of the season for a second straight week (5.5/14). Still, it ranked as the No. 1 show of the night in the demo as well as in total viewers (13.56m).

NBC was flat vs. the same night last year, but the other major nets were all down.

At Fox, “That ’70s Show” won at 8 in 18-49 (4.0/12) and 18-34 (4.5/15), but a special “That ’80s Show” dipped to a second-place tie in 18-49 with a repeat “Frasier” (3.6/10) — behind the second half of “Laverne & Shirley” (3.8/10).

As for “24,” it improved on its lead-in but its 3.8/9 in 18-49 kept the net third for the 9 o’clock hour.

The WB’s “Gilmore Girls” surged to series highs in adults 18-34 (3.1/10) and persons 12-34 (3.5/11), even topping UPN’s “Buffy the Vampire Slayer” in young male demos.

And “Smallville” won its hour among viewers under 35, persons 12-34 (4.2/12) and men 18-34 (4.5/13), while finishing second to NBC in adults 18-34 (3.9/11).

UPN showed big year-to-year gains vs. its weak Tuesday scores last season, but “Buffy the Vampire Slayer” fell to firstrun season lows (4.07m, 2.2/6 in 18-49).

MTV’s “Osbournes” rebounded from an off week to post strong season finale numbers (7.25m, 4.3/11 in 18-49) — just off its highs of two weeks ago. It won its 10:30 half-hour in adults 18-34 (6.3/18) and teens (3.9/20).