ESPN’s mega-successful “Monday Night Football” franchise has taken a significant hit in the ratings this season.

According to Nielsen data, “MNF” slipped almost 10 percent in viewers this year, its sixth season — quite a dropoff from last year, when the telecast broke ratings records on ESPN.

This year, the telecast averaged 13.3 million viewers, down from 14.7 million viewers in 2010.

The Dec. 26 Saints-Falcons game averaged 15.6 million viewers — compared to the Dec. 27, 2010 Saints-Falcons game (19 million viewers).

Despite the drop, “MNF” remains cable’s most-watched program, and ESPN’s biggest weekly draw.