Credit: Kelsey McNeal

Whether they came for the dancing or to gawk at Cloris Leachman‘s cleavage, most TV eyes last night were tuned into ABC’s two-hour premiere of Dancing With the Stars (pictured). The first episode reached 21.1 million viewers, according to overnight ratings, down about 3 percent from last March’s debut of 21.8 million, but still a number that would please even Len Goodman. Those Stars fans apparently don’t care much for William Shatner and James Spader, however, as the season premiere of Boston Legal only managed 9.5 million viewers, losing more than half of Stars‘ audience.

Meanwhile, CBS debuted its Monday night lineup to strong numbers, especially for How I Met Your Mother (9.7 mil) and Two and a Half Men (14.9 mil), which were up 20 percent and 10 percent, respectively, from last year’s debuts. The Big Bang Theory was slightly down from last year’s premiere (9.4 mil vs. 9.5 mil), while CSI: Miami drew a sunny 16.9 million viewers, 1.8 million more than last season’s debut episode. Newbie series Worst Week didn’t have the worst debut, attracting 11 million viewers, though that is a loss of almost 4 million from its Men lead-in.

The biggest disappointment of the night would have to be NBC’s flailing Heroes. The network’s 8-9 p.m. recap special drew an un-heroic 6 million viewers. Then, the two-hour premiere reached only 10 million viewers, down about 29 percent from the 14.1 million who tuned in for season 2’s premiere. (Last year, NBC was able to get Nielsen to add together Heroes’ ratings for the initial Monday night premiere along with a Saturday repeat to come up with a final number of 17 million.)

While DVR playback should boost the Heroes premiere numbers, that lukewarm start could still be a sign that the series’ superpowers are weakening

UPDATE: Wondering how The CW’s Monday lineup fared against all this fresh competition?

Pretty solidly, actually. Gossip Girl reached 3.4 million viewers, down about

300k from the previous week’s series high of 3.7 million. Meanwhile, Chad

Michael Murray and the folks of One Tree Hill also saw a decline of 300k,

with this week’s episode nabbing 3.1 million pairs of eyes.