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Ratings for the NFL’s season opener on Thursday night fell 8 percent from last year’s opener — to their lowest level in a decade.

The decline came even after the TV audience for last year’s opener declined 19 percent from 2016’s opener, statistics out Friday revealed.

The “Thursday Night Football” telecast on NBC, delayed 45 minutes due to severe weather in the Philadelphia area, averaged a 13.4 overnight rating.

That made it the lowest season opener in 10 years, according to Sports Media Watch — and breathed new life into fears about the NFL being unable to extricate itself from a structural decline.

The game, which saw the Super Bowl champ Philadelphia Eagles beat their NFC rival Atlanta Falcons 18-12, drew a 32.9 overnight rating in the City of Brotherly Love. It drew a 19.8 rating in Atlanta.

Despite the continued ratings erosion for the NFL, the league is still the leader by far in drawing eyeballs to the screen. The broadcast of the game, with its 9:05 p.m. kickoff, doubled the combined primetime average of the other Big 4 networks — ABC, CBS and Fox.

“On the plus side, the NFL’s still the tallest midget by a mile,” a sports media consultant told The Post, a reference to even steeper declines in the networks’ non-sports programming.