Kirstie Alley and Maksim Chmerkovskiy Kirstie Alley and Maksim Chmerkovskiy

Dancing with the Stars trotted back to a formidable average of 22.3 million fans, though that's down from the 24.2 million who tuned in for last spring's debut.

The two-hour, 12th-season opener, airing at 8/7c, put up a 5.1 rating in the advertiser-coveted 18-to-49 demographic — down 20 percent from the year-earlier 6.4 rating. Still, ABC easily outpaced the other networks for the second straight Monday night.

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Against Dancing in the first hour of prime time, Fox's House had the second-biggest audience (9.3 million viewers). On CBS, How I Met Your Mother featuring John Lithgow as Barney's father drew nearly 8 million viewers and a fresh episode of Mad Love  got 6.5 million. Chuck drew 4.3 million viewers  on NBC and a 90210 rerun was watched by a meager 778,000 on the CW.

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At 9/8c, another Two and a Half Men repeat got 9.1 million viewers. Fox's The Chicago Code totaled 6.3 million, and a repeat of CW's Gossip Girl drew 529,000, while at 9:30, a fresh episode of CBS' Mike & Molly lured 9.6 million. Also, The Event on NBC continued its free fall, with 4 million viewers.

Castle benefited from Dancing's boffo lead-in in prime time's final hour, dominating with some 12.7 million people, while the start of Larisa Oleynik's story arc on CBS' Hawaii Five-0  had 9.8 million viewers and Harry's Lawwhich has been NBC's top-rated show and rose to No. 17 in the latest weekly rankings — reeled in 8.2 million.