It looks like Stephen Colbert's reign as the new late-night ratings king lasted just 24 hours.
Order was restored on night two of the competition between Colbert's Late Show and The Tonight Show Starring Jimmy Fallon, with Fallon reclaiming the lead in the coveted demographic of adults ages 18 to 49.
UPDATE: In updated "fast official" ratings from Nielsen, The Tonight Show topped the Late Show on Wednesday night with a 1.2 rating in adults 18-49, up from 0.9 on Tuesday. That nearly equals the combined ratings of Late Show (0.8, down from Tuesday's 1.4) and Jimmy Kimmel Live (0.5, up from Tuesday's 0.4). NBC said this was Tonight Show's highest rating in the demographic since February.
The Tonight Show also won the night in total viewers, with 4.1 million, compared to Late Show's 3.7 million and Kimmel's 1.8 million.
Earlier Thursday, Nielsen local people meter ratings (which cover 25 markets) for all three shows were similar to the "fast official" ratings. Although, Colbert had maintained a slim lead in the household ratings for Nielsen's 56 metered markets, edging out Fallon 3.2 to 3.1. The numbers shifted in Fallon's favor after the national ratings were tallied.
While some of the major audience shifts can be explained by viewers who had only wanted to sample Colbert's premiere, Fallon also smartly slotted Justin Timberlake as a Wednesday guest, and the duo performed the sixth iteration of their wildly popular "History of Rap" medleys.
Fallon stacked the deck with another popular Tonight Show segment: "Lip Sync Battle," where he faced off with Ellen DeGeneres.
Colbert, meanwhile, debuted two potential recurring segments of his own. The first: "Big Questions With Even Bigger Stars," in which he and Scarlett Johansson pondered some of life's great (and not-so-great) mysteries:
In "The Hat Has Spoken," Colbert instituted some important new laws of the land, with the help of his furry hat:
While Fallon and Colbert are friendly and have none of David Letterman and Jay Leno's animosity—Fallon made two appearances on Colbert's premiere episode—their respective networks are intent on grabbing as many viewers, and advertising dollars, as possible. That's why Fallon loaded up on A-listers to counter Colbert's debut week, with the biggest Tonight Show booking saved for Friday: Donald Trump.
Wednesday's ratings shift also spread to the 12:30 a.m. shows, where NBC's Late Night With Seth Meyers on NBC was back on top over CBS' The Late Late Show With James Corden in both adults 18-49 (0.6 versus 0.3) and total viewers (1.7 million versus 1.0 million).