CBS's controversial modern-day Sherlock Holmes drama launched with an average audience of 13.3 million, scoring a slot-winning demo rating of 3.1 in the advertiser-friendly '18-49 adults' demo.
Screened in the 10pm hour and starring Jonny Lee Miller in the role of Holmes, Elementary came in higher than ABC's Scandal (7m/2.2), the latter's rating up year-on-year.
Grey's Anatomy topped the 9pm hour for the Alphabet Network with 11.5m (4.3) for its ninth season premiere, a rise of two-tenths on last year's season eight opener.
Coming runner-up in terms of 18-49 adults, Person of Interest managed 14.3m (2.9), while Glee entertained 5.9m (2.5) on Fox, and The CW's Next had 683k (0.3).
The Big Bang Theory's opener amused 15.3m (4.8) at 8pm, topping the night in total viewers and with young adults.
Two and a Half Men followed at 8.30pm with 12.4m (3.5), under half of its gigantic ratings inflated by Ashton Kutcher's debut last year.
The X Factor USA dipped to 9.2m (3.2) on Fox in the 8pm hour.
Published figures for NBC are likely to be inaccurate due to an overrun of its Thursday Night Football programme.
Averages currently stand at 5.4m (1.7) for a Saturday Night Live update, 4.5m (1.8) for Up All Night, 5.2m (2.4) for The Office, 4.5m (2.1) for Parks and Recreation, and 4.2m (1.2) for Rock Centre with Brian Williams.