“The Late Show With Stephen Colbert” scored its biggest margin of victory in total viewers ever thanks to the CBS late-night show’s “Russia Week” for the frame ending July 21.

The week of shows covered the host’s recent trip to St. Petersburg and Moscow. It won the week in viewers by its largest margin since the show’s premiere in September of 2015, according to Nielsen live-plus-same-day ratings, with an average of 2.87 million viewers per episode. The show topped “The Tonight Show Starring Jimmy Fallon” by 450,000 viewers for the week, with the “Tonight Show” averaging 2.42 million viewers per episode. “The Late Show” was also up 14% compared to the same week last year.

However, Fallon was still the top-rated late night show in adults 18-49. “The Tonight Show” averaged a 0.59 rating in the key demo, topping Colbert (0.43) and ABC’s Jimmy Kimmel (0.37).

Colbert and Fallon have been battling it out in the ratings for months, with Colbert’s total viewer numbers surging ever since Donald Trump’s election.

Back in May, Colbert officially beat Fallon in total viewers for the traditional September-May television season. Colbert’s victory marked CBS’ first late-night win since the 1994-1995 season, excluding 2009-2010 when NBC replaced Conan O’Brien with Jay Leno midway through the season. “The Late Show” was also the only late-night program to post year-to-year growth in total viewers. However, Fallon beat Colbert in adults 18-49.