The competition between Stephen Colbert’s “The Late Show” and Jimmy Fallon’s “Tonight Show” intensified on the second night of Colbert’s run. “Tonight Show” reclaimed the top spot in total viewers and adults 18-49 after dropping to No. 2 on Tuesday against the heat of “The Late Show’s” premiere push.

“The Tonight Show” averaged 4.06 million viewers on Wednesday and a 1.2 rating in the adults 18-49 demographic. “The Late Show” delivered 3.66 million viewers and a 0.8 in adults 18-49. That compared to 6.6 million viewers for Tuesday’s debut.

Fallon’s “Tonight Show” was enhanced by guest Justin Timberlake, who joined with Fallon for a “History of Rap” performance that went viral even before the episode aired on linear TV.

“The Late Show” decline was entirely expected following the tsunami of promotion for Tuesday’s launch. “Late Show’s” numbers were up year-over-year, compared with David Letterman’s last season, by 70% in total viewers, by 67% in adults 25-54 (1.0), 60% in adults 18-49 and 150% in adults 18-34 (0.5).

See More: Watch: Jimmy Fallon and Justin Timberlake Debut ‘History of Rap 6’

ABC’s “Jimmy Kimmel Live” has been overshadowed for the past two nights by the CBS-NBC duel. On Wednesday, “Kimmel” delivered 1.85 million viewers and a 0.5 in adults 18-49.