More reliable numbers won’t be available until later today, but Fox’s miniseries return of “The X-Files” opened to predictably strong ratings following an NFL playoff game on Sunday night — and of course the big test will come tonight when it kicks off Monday for the network in its regular timeslot. The drama revival got nowhere near the lead-in it might have gotten if it had followed the late-afternoon AFC Championship game on CBS, which delivered the best rating in decades for the contest deciding which team from the conference advanced to the Super Bowl.

According to Nielsen estimates, the 3:05-6:45 p.m. ET game between the New England Patriots and Denver Broncos on CBS averaged a monster 31.8 household rating/53 share in the overnights, peaking with a 36.6/57 from 6-6:30 p.m. ET. The Broncos’ 20-18 victory, in the 17th matchup all-time of legendary quarterbacks Peyton Manning and Tom Brady, notched the highest rating for the AFC Championship in 29 years (since an overtime contest between Denver and Cleveland on NBC did a 31.9 rating).

It’s also the highest early-window game rating for both the AFC or NFC Championship since 1987, up 9% from last year’s Green Bay-Seattle overtime contest on Fox (29.1/52). In total viewers, the New England-Denver game drew a whopping 53.3 million — the second largest audience for the AFC title game in 39 years (behind only the 54.8 million who watched the New York Jets take on the Pittsburgh Steelers in the late window on CBS in 2011). No early game on Championship Sunday has rated higher since at least 1978, according to CBS records.

As for Fox, the NFC Championship game between the Arizona Cardinals and Carolina Panthers, two teams with considerably less national following, averaged a 26.8 household rating/40 share in the overnights — up 19% from last year’s primetime conference championship game between Indianapolis and New England on CBS (24.2/39) — and 45.7 million total viewers. It didn’t help, of course, that the Arizona-Carolina game turned into a lopsided affair, with the home team Panthers prevailing 49-15 to advance to the Super Bowl for the second time in franchise history.

The lack of drama late in the game did not allow Fox to funnel as many viewers into “The X-Files” as it may have hoped. Nielsen will issue more accurate time zone-adjusted averages later today or tomorrow for the premiere, which started at 10:24 p.m. ET.

Sunday’s preliminary viewership in the 10:30 p.m. half-hour was 13.5 million and a 5.1 rating in adults 18-49, and the program’s averages should be a little higher than this in the nationals (perhaps in the 15 million-to-16 million range). “The X-Files,” which was among the most popular programs in Fox history, peaked in its fourth season (1996-97) when it averaged nearly 20 million viewers per episode. Its all-time high in viewership came on Jan. 26, 1997, when the episode titled “Leonard Betts” averaged 29.1 million viewers when it followed the network’s coverage of the Super Bowl game between New England and Green Bay. Its series finale in 2002 drew 13.2 million viewers.

See More: ‘The X-Files’ Premiere Recap: Lost in Space

Fox is hoping the limited-run return of “The X-Files” can provide a strong ratings lead-in for new drama “Lucifer,” which bows tonight at 9 following the sci-fi series.

Elsewhere on Sunday opposite football and “The X-Files” on Fox, CBS kept the lights on with “60 Minutes” (1.2/3 in 18-49, 8.4 million viewers overall) and repeats of “Madam Secretary” (0.7/2 in 18-49, 5.2 million viewers overall) and “NCIS” on a special night (0.8/2 in 18-49, 5.9 million viewers overall). And NBC did the same with a repeat of 2011 theatrical hit “Bridesmaids” (0.9/3 in 18-49, 2.7 million viewers overall).

ABC struggled to be noticed with its lineup of “America’s Funniest Home Videos” (0.8/2 in 18-49, 4.5 million viewers overall), “Galavant” (0.5/1 in 18-49, 2.1 million viewers overall) and a special encore of last Tuesday’s low-rated second-season premiere of “Marvel’s Agent Carter” (0.4/1 in 18-49, 1.4 million viewers overall).