Nick Offerman (left) and Murray Bartlett in ‘The Last of Us.’

Courtesy of HBO

The third episode of HBO’s The Last of Us delivered another week of ratings growth.

Sunday’s installment brought in 6.4 million cross-platform viewers, up from 5.7 million the previous week and 4.7 million for its Jan. 15 premiere. The uptick on Sunday came despite the episode debuting at the same time as the hugely watched AFC Championship game on CBS.

HBO also says that four of its current series, including The Last of Us, have averaged more than 15 million viewers for their most recent seasons.

The Last of Us‘ third episode took a detour from central characters Joel and Ellie (Pedro Pascal and Bella Ramsey) to tell the story of Bill (Nick Offerman) and Frank (Murray Bartlett), who maintain a 20-year romantic relationship even as the world falls apart. “There are these incredibly tender and authentic human scenes in the midst of this monstrous world,” Bartlett told The Hollywood Reporter about the episode.

The series’ first two installments are averaging 21.3 million viewers to date across all platforms, per HBO — with the great majority of that coming from streaming on HBO Max (HBO doesn’t release detailed streaming figures, but with a first-night, on-air audience of only about 610,000 people, the math tilts heavily toward streaming). HBO has already renewed The Last of Us for a second season.

The drama joins season one of House of the Dragon (29 million viewers) and the most recent seasons of Euphoria (19.5 million) and The White Lotus (15.5 million) in averaging above 15 million viewers per episode over the course of their runs — the first time HBO has had that many shows across all genres drawing audiences of that size.

By comparison, in its pre-streaming heyday in 2002, the fourth season of The Sopranos pulled in an estimated 18.2 million viewers per episode (including delayed and on-demand viewing). That same year, season five of Sex and the City averaged 13.8 million viewers and season two of Six Feet Under, 12.1 million.