CBS News’ “60 Minutes” drew just over 6.5 million viewers for the second episode of its new season Sunday, according to preliminary Nielsen ratings — slightly ahead of the comparable episode a year ago.

The second episode of last season attracted 6.454 million viewers, according to Nielsen data.

In the key 25-to-54 demographic, Sunday’s episode drew 1.1 million viewers, according to the preliminary stats — about 20% higher than the 917,000 viewers in the demo who watched the comparable second episode last season.

CBS News has a lot riding on the ratings — all eyes are on “60 Minutes” after a tumultuous shakeup of the show’s staff that unfolded through the summer. This season is the first full one under the network’s Editor-in-Chief Bari Weiss, who hired new executive producer Nick Bilton in May.

Sunday’s audience was nevertheless down 18% from this season’s Sept. 13 premiere, which drew 7.935 million viewers in final Nielsen Big Data + Panel ratings.

Viewership among adults 25 to 54 fell 30% from the premiere, according to the preliminary figures.

The season debut was down from a year earlier, when the “60 Minutes” premiere drew 10.026 million viewers. That amounted to a 21% year-over-year decline in total viewers, while the 25-to-54 audience fell 33%.

Unlike last week’s premiere, Sunday’s broadcast did not have a nationally televised NFL game as its direct lead-in. The premiere followed an NFL audience of 18.4 million viewers.

Sunday’s episode, which included a heavily promoted interview with Patrick Clancy, fell to 6.3 million total viewers and 956,000 adults 25 to 54 in its final quarter-hour, according to the preliminary Nielsen data.

Fox’s “Best Medicine” and CBS’s “Big Brother” both drew larger audiences in the 25-to-54 demographic Sunday night.

Final Nielsen ratings for the episode are expected later Tuesday.

“60 Minutes” held onto more of its premiere audience than it did a year ago, according to the preliminary data.

This season’s second episode was down about 15% from the premiere, meaning the show retained roughly 85% of its opening-week audience, according to the preliminary Nielsen figures.

By comparison, last season’s second episode fell about 33% from its premiere, retaining roughly two-thirds of the audience.

A source noted that a sizable week-two decline is not unusual because the premiere benefits from following two national NFL games, but the second episode airs after a single-header game that varies from region to region.

The Post has sought comment from CBS News.