There were some megastars in the house for the Season 20 kickoff of ABC’s Dancing With The Stars (1.9/6) last night, but no high kicks — at least ratingswise. With Rumer Willis among the celebs strutting their stuff this year, parents Bruce Willis and Demi Moore were there to show support during the two-hour premiere Monday. Still, the star power didn’t provide much of a step for DWTS, which had its lowest season premiere ever among adults 18-49. Even though the dancing competition was the most-watched show of Monday’s primetime with 12.4 million tuning in, the series dropped 26% in the key demo from its last spring debut on March 17, 2014.

Viewershipwise, last night’s debut was down 21% from the 15.66 million who watched the two-hour Season 18 premiere last year. Compared to the Season 19 opener on September 15 last year, last night tumbled 17% among 18-49s. With that, lead-out Castle (1.5/5) remained basically steady with its last original February 23 with a 6% dip.

In the final tally, ABC won the night in total viewers with 12.372 million and NBC took the demo top spot with 2.7/8 rating.

As in most previous seasons, DWTS was up against The Voice (3.3/10) last night and it was the latter that won that unscripted standoff. The NBC singing competition was the highest-rated show of the night but took a 13% hit itself from last week in the demo. In preliminary numbers, that’s the worst result The Voice has had this season so far – though the show is commonly adjusted in later ratings, so that could change. The rest of NBC’s night saw Voice lead-out The Night Shift (1.5/5) rising 15% from last week.

CBS and Fox were a mix of encores and originals with the former’s new Mike & Molly (1.9/6) down 10% from last week and the latter’s The Following (1.1/3) even with last week — a series low for the Kevin Bacon-starrer. In total ratings Monday night, Fox pulled in a 0.9/3, which put it behind third-place Univision’s 1.0/3 by a nose.

The CW, which got a 0.5/2 overall rating, saw The Originals (0.6/2) rise 20% from the season low of last week. Lead-out Jane The Virgin (0.4/1) fell 20% from its March 9 show to match a low among adults 18-49 in preliminary ratings.