HOLLYWOOD — NBC has successfully launched its third new unscripted series of the summer, as auds yukked it up Tuesday night with the two-hour premiere of “Last Comic Standing.”

Meanwhile, Fox’s “American Juniors” lost more than a fourth of its audience in week two but still led its hour, while the net’s new drama “Keen Eddie” is looking shaky.

According to Nielsen, “Last Comic Standing” (4.5/13 in adults 18-49, 9.72 million viewers overall) dominated its 9-11 p.m. timeslot, topping second-place ABC’s repeats by 55% in the demo. The standup comedy competish also delivered the best men 18-49 score for any of the 11 contest series to bow since Fox’s “Joe Millionaire” in January (4.4/13).

Promising debut comes on the heels of a potent preem for “Fame” and a solid start for “For Love or Money.”

Much like the “Fame” premiere on a Wednesday two weeks earlier, “Comic” provided NBC with considerable time-period improvement, delivering the net’s second-best score in the Tuesday 9-11 slot in 18 weeks.

“Comic,” created and hosted by Jay Mohr, averaged a 4.3/12 in adults 18-49 from 9 to 10 (its regular timeslot) and then overwhelmed repeats on ABC and CBS from 10 to 11 (4.7/13).

At Fox, “American Juniors” (3.5/12 in A18-49, 8.73m) led at 8 but was down 27% in 18-49 from its premiere and saw its advantage over NBC’s second-place “Dog Eat Dog” (3.1/11 in A18-49) shaved from 41% to 13%.

Dropoff suggests that “Juniors,” which has a spot reserved on Fox’s fall lineup, will likely score more like NBC’s modestly performing “America’s Most Talented Kid” than like “Idol” itself. Next week’s result could be key in assessing the show’s long-term viability.

At 9, “Keen Eddie” placed third in 18-49 (2.2/6), declining 31% from its OK premiere a week earlier.

In the same hour, UPN’s “America’s Next Top Model” (1.7/5 in A18-49, 3.38m) placed second in women 18-34 (3.5/10) and just a tick behind “Keen Eddie” in adults 18-34 (third-place 2.2/7). In its fourth outing, “Model” was down from its series highs set a week earlier.