Fox made it four consecutive nightly victories in young adults Tuesday as a double dose of “That ’70s Show” posted groovy demos, dominating the opening hour.

According to Nielsen, “That ’70s Show” won its hour by all key demo measures, including by an impressive 6 shares in adults 18-49 over second-place ABC’s “Who Wants to Be a Millionaire” (5.7/17 vs. 3.8/11). Comedy’s second of two original episodes delivered Fox’s best 18-49 score in the Tuesday 8:30 slot (6.1/17) since March 1999 (“Opening the Tombs”); regular slot occupant “Titus” nabbed a best-ever 6.0/14 three months ago.

News wasn’t as good at 9, where “Dark Angel” (4.1/11 in A18-49) placed third behind comedies on NBC and ABC, but the rookie drama has rebounded with two solid efforts after hitting a season low last month (3.8/10).

Edging Alphabet

For the night, Fox topped second-place ABC by 1 share in adults 18-49 (4.9/14 vs. 4.6/13) and also won easily, as usual, in adults 18-34 (5.6/17) and teens (4.7/17). Compared with the opening Tuesday of last May, net was up by 88% in 18-49 (4.9 vs. 2.6).

ABC captured its ninth straight Tuesday in total viewers, although “Millionaire” attracted its smallest aud ever for a firstrun Tuesday hour (15.31m). In adults 18-49, net received solid second-place finishes from 8 to 10 and then easily took the night’s final hour with “NYPD Blue” (5.5/15), which also drew more viewers than a firstrun seg of CBS drama “Judging Amy” for a fourth straight time (13.54m vs. 12.78m).

NBC had a fairly strong night as “Frasier” (17.57m, 7.4/19 in A18-49) logged its best numbers since Feb. 20 and “Dateline” (10m, 4.1/11) its best since March 13. But opening-hour comedies “Fighting Fitzgeralds” (5.29m, 2.0/6) and “3rd Rock From the Sun” (5.58m, 2.3/6) fell to season lows and 9:30’s “Three Sisters” (11.89m, 5.2/13) retained a lowest-yet 70% of its “Frasier” 18-49 lead-in.

CBS was second in total viewers but fourth in all demos as all three of its programs matched or set season demo lows. Compared with the same night a year ago, the Eye was off by 18% in viewers (11.2m vs. 13.6m) and by 16% in adults 18-49 (3.1 vs. 3.7).

Through six nights of the May sweep, NBC continues to lead in adults 18-49 (4.9/14) but Fox (4.3/13) has pulled close with its four-night winning streak. CBS continues to lead in total viewers (12.8 million), ahead of second-place NBC (11.5 million).