Even a power outage that preempted play for more than 30 minutes couldn’t derail ratings for the Super Bowl, as Sunday’s game on CBS between the Baltimore Ravens and San Francisco 49ers averaged a big 108.4 million viewers.

The national estimate from Nielsen, which as always counts only in-home viewing, is down from the last two years but is the third largest audience on record for any program. The previous high was set last year for the New York Giants and New England Patriots (111.35 million). Since drawing 86.1 million viewers for the 2005 game on Fox, viewership for the Super Bowl had grown every year until this year.

Following the game and postgame show on CBS, an original episode of rookie drama “Elementary” averaged a 7.8 rating in adults 18-49 and drew 20.8 million viewers overall, series highs as expected but the smallest crowd for an entertainment program after the big game since ABC’s “Alias” drew 17.4 million in 2003; like “Elementary,” “Alias” didn’t start until after 11 p.m. ET.

Sunday’s telecast of “Elementary” drew the largest demo ratings for any series this season.

Last year, “The Voice” on NBC did a 16.3 rating in 18-49 and 37.6 million viewers overall — though it benefited from starting 52 minutes earlier than “Elementary.”

The Super Bowl would not have drawn such a big number if the 49ers couldn’t rally following the 34-minute power outage early in the third quarter, which was broken out by Nielsen and is not included in the game averages. It will never be known if the break helped change momentum in San Francisco’s favor, but the game clearly became more compelling once the 49ers were able to score a couple of second-half touchdowns to get back in it.

And, of course, the nail-biter finish — with the 49ers having four chances from the 5-yard line to win the game in the final two minutes — didn’t hurt. The Ravens prevailed, 31-28.

In Nielsen’s metered-market households, the 8:45-9:15 p.m. portion did a 46.5/68, but viewership spiked from there. The 9:15 p.m. quarter-hour did a 47.9/68, the 9:30 p.m. quarter-hour did a 49.6/70, the 10 p.m. portion did a 51.3/73 and the 10:30-10:47 p.m. concluding portion of the game did a 52.9/75.

The 8 o’clock half-hour containing the Beyonce concert at halftime earned a 48.2/71, right in line with the surrounding half-hours of football action.

Nationally, the overnight score for the game (48.1 household rating/71 share) was up 1% from last year’s 47.8/71 for New York Giants-New England on NBC and the highest on record — also topping the previous high of 47.9/71 for Green Bay-Pittsburgh on Fox.

Baltimore grabbed the top scores among Nielsen’s metered markets (a 59.6 rating/83 share), with host city New Orleans second (57.1/77).

The other networks battled for crumbs Sunday, with Fox’s repeat “Family Guy” faring best among adults 18-49 (0.9/2) and an encore of ABC’s “America’s Funniest Home Videos” drawing the most total viewers (a mere 2.6 million).