An NFL lead-in gives the second-season premiere of '911' double-digit improvements over its series debut.

Fox's 911 opened its second season on Sunday, Sept. 23 with its best ratings to date, with an assist from the NFL. NBC also got good returns from its primetime football broadcast, posting double-digit gains over the same night in 2017.

Season two of 911 debuted to a 2.6 rating among adults 18-49 and 9.8 million viewers in time zone-adjusted fast nationals. That's a 44 percent improvement on the show's previous same-day high of 1.8 in the demo (reached twice last season) and a 43 percent jump over the previous total-viewer best of 6.83 million for the series premiere. It was the most-watched Fox entertainment program since the season three premiere of Empire in September 2016 (excluding the post-Super Bowl premiere of 24: Legacy in 2017)

Sunday Night Football once again dominated the night and posted its second straight week of year-to-year growth in the early numbers.

The Detroit Lions' victory over the New England Patriots earned a 13.6 rating/23 share in metered-market households, up 18 percent from a year ago (11.5/20). The combined ratings for the afternoon NFL windows improved slightly in the overnights as well.

ABC's game shows and CBS' Big Brother didn't fare as well Sunday. The finales of Celebrity Family Feud (0.6) and The $100,000 Pyramid (0.6 and 0.5 for two episodes) posted season lows for ABC. The next-to-last Big Brother of the season came in at 1.3, down four tenths of a point week to week.

NBC averaged a 5.1 in the 18-49 demo for all of primetime, pending updates. That's more than double the 2.4 (also pending updates) for second-place Fox. CBS came in third at 0.8, beating ABC's 0.6.

Sept. 23, 10:11 a.m. Updated with adjusted ratings figures for 911.