It felt like Premiere Week last night with three new series debuting as the major networks held back their rollouts to avoid a pre-emption from the first presidential debate last Wednesday and the CW opted for a late fall launch this year.

The CW received good ratings news for the premiere of Arrow, which drew a very big for CW standards audience of 4 million to become the network’s most-watched series premiere since flagship The Vampire Diaries. This was the CW’s largest viewership in the Wednesday 8 PM time period in three and a half years, since the May 2009 season finale of America’s Next Top Model, and the most watched CW telecast on any night in three years, since November 11 2009.

What’s more, Arrow (1.3/4 in adults 18-49, 1.1/4 in 18-34) tied NBC in the 8 PM hour in total viewers, 18-49 and 18-34. The higher 18-49 number for the superhero drama indicates a broader, older-skewing show in the vein of Nikita vs. the CW’s normal fare. Arrow also boosted its lead-out, veteran Supernatural (2.6 million, 1.0/3), which jumped 40% in viewers from its season premiere last week.

The rest of the action last night was at 10 PM, where ABC premiered its highest-profile new fall drama Nashville and NBC launched firefighter drama Chicago Fire. Nashville (2.8/8 in 18-49, 9 million) opened OK. It won the 10 PM hour in 18-49 but was down 15% from the debut of Revenge in the hour last fall. Both soaps had an hourlong Modern Family lead-in, though last night’s Modern Family ratings (4.7/13 at 9 PM, down 15% from its season premiere two weeks ago; 4.9/12 at 9:30 PM) were lower than last fall’s hourlong season premiere that led into Revenge. Between the first and second half-hour, Nashville dropped a half rating point in 18-49, in line with the drop-off for the Revenge premiere last fall. In the 8 PM hour, ABC’s The Middle (2.4/7) was up 9% from last week, while The Neighbors (1.9/5) was flat.

The premiere of Dick Wolf’s new show couldn’t match the opener of his old one as rookie Chicago Fire (1.9/5, 6.3 million) was down 21% from the season premiere of veteran Law & Order: SVU in the hour last fall. Chicago Fire was the lowest drama series debut on the Big 4 this fall, not counting goner Made In Jersey and almost-goner The Mob Doctor. On the positive side, Chicago Fire held steady from the first to the second half-hour (both at 1.9 rating) and was NBC’s highest-rated program of the night, building on its lead-in, Law & Order: SVU (1.8/5, down 14% from its two-hour premiere two weeks ago), a rare feat for a 10 PM show. As we noted above, NBC’s 8-9 comedies Animal Practice (1.1/3, down 15% from last week) and Guys With Kids (1.4/4, down 13%) tied the CW’s Arrow in the hour. ‘Nuff said.

CBS’ Survivor: Philippines (2.6/8) and Criminal Minds were down from last week by 13% and 3%, respectively. But somewhat surprisingly, CSI (2.6/7) perked up against the new 10 PM competition, up a tenth from its season premiere two weeks ago. CBS (2.8/8 in 18-49, 10.5 million viewers) won the night in total viewers. Fox was No. 1 in 18-49 with The X Factor (3.4/9), even with last week’s fast national.