In its third Monday seg, some strain is showing in NBC’s “Weakest Link,” with the show taking a tumble in the ratings. Quizzer still posted solid numbers in a tough time period, but it certainly isn’t the runaway hit it resembled earlier on.

According to Nielsen, “Link” finished second in adults 18-49 for its 8 o’clock hour (4.2/13), behind Fox’s “Boston Public” (4.9/15) and just ahead of CBS’ comedies (4.1/12). It was off by 28% from its strong week-two score (5.8/16), when it dominated the hour by all measures.

It remained the hour’s top draw among adults 18-34 (4.7/15), down 27% week-to-week. Also chipping away at its numbers in the young demo was ABC’s preem of “Armageddon.”

In total viewers, “Link” (11.11 million) finished a close second to the Eye’s “King of Queens” and “Yes, Dear” (combined 11.21m); gamer was down 21% week-to-week.

Still valuable

Still, even a weaker “Link” provided a considerable boost for NBC. Compared with the opening Monday of last May’s sweeps, NBC was up 16% in adults 18-49 (4.4/12 vs. 3.8/10).

Fox won the night in every key demo, as both “Boston Public” (4.9/15) and “Ally McBeal” (6.4/16) won their hours in 18-49. It’s the net’s third straight nightly victory in the demo.

CBS was first in total viewers, but a rare fourth-place finisher in 18-49, as “Everybody Loves Raymond” fell to a firstrun season low (5.7/14) and “Family Law” was a noncompetitive third at 10 (3.5/9). “Raymond” slipped behind the first half-hour of Fox’s “Ally McBeal” in adults 18-49 (5.7/14 vs. 5.9/15) for the first time this season, but remained the night’s most-watched show (17.07m).

‘Raymond’ falls

“Raymond’s” dip coincided with the best demo perfs in the 9 o’clock hour in months for shows on three competing nets: ABC’s movie, NBC’s “Dateline” and the WB’s “Roswell.” Latter show, which, according to some reports, is not expected to return to the Frog next fall, retained a best-ever 100% of its “7th Heaven” lead-in among women 18-34 (3.0/8), while delivering its best scores in young-female demos since November.

“Armageddon,” which built throughout the night and dominated its final hour, gave ABC its best male demos for a Monday movie this season and boosted the net to second in adults 18-34 for the night.