Second season premiere of 'Thrones' far outpaces Sunday night rivals 'Mad Men' and 'The Killing' on AMC.

"Game of Thrones" was easily the top-ranked scripted series on cable on Sunday night, too, far outpacing the second episode of the fifth season of "Mad Men," which posted a strong 2.94 million viewers. "Thrones" made even shorter work of "The Killing," which netted 1.8 million for its second season premiere. The AMC murder mystery's ratings tumble likely owes thanks to its controversial season-one cliffhanger, which refused to resolve the season-long mystery of who killed Rosie Larsen.

With more than four million viewers back in the Westeros fold, a season-three pickup for "Thrones" seems all but guaranteed. Indeed, it's possible that we're on the verge of a two-season order; producers and show-runners David Benioff and D.B. Weiss have been very open about their desire to split the third novel in George R.R. Martin's "A Song of Ice and Fire" series, titled "A Storm of Swords," into two distinct seasons, as opposed to the tried-and-true one-book-per-season method that's worked so well so far.

"As George and all his fans have said for a long time, there's no way to do it in a single season, so it's being broken into two," Benioff told EW.comlast month about his intentions to turn "Storm" into two seasons of "Thrones." "We're still kind of figuring out exactly what goes where. We don't want it to feel like a two-part season."