One network had an especially tough night in the ratings Tuesday, with two shows hitting all-time lows and the network’s average rating in the key demo placing it a distant fourth for prime time — and for a change, it wasn’t NBC.

The struggling network was ABC, which saw “Cougar Town” and “Dancing with the Stars” both hit historic lows. “Cougar Town” aired back-to-back episodes during the 8 p.m. hour, and both episodes averaged only a 1.0 rating in the key 18-49 demo in Nielsen overnights, according to TVbytheNumbers.com. The 1.0 was off 33% from last week’s 1.5, and an all-time low for the series.

The “Dancing” results show followed, pulling a 2.2 — down 8% from a week ago and an all-time series low for a results show.

The network’s night did finish on an up note, with the “Private Practice” season finale at 10 p.m. rising a hefty 29% from the series low set a week ago.

For prime time overall, CBS was the winner with a 3.2 average rating in viewers 18-49, topping NBC (2.8 average) and Fox (2.8). ABC barely held off Univision for fourth place, averaging a 1.7 to Univision’s 1.6.

Total viewers saw CBS well out front with 16.1 million to 8.6 million for NBC. ABC pulled ahead of Fox, drawing 7.8 million to Fox’s 6.0 million. Univision had 4.1 million.

CBS’s “NCIS” season finale was the top show of the night with a 3.5 average rating in 18-49, just ahead of the 3.4 for NBC’s “America’s Got Talent” — the best number of the season for NBC in the time period. Fox’s back-to-back installments of “Glee” had to settle for a 2.4 and a 2.5, down from last week’s 2.7.