HBO's biggest original show scored the largest audiences in the premium network’s history.

The series finale of "Game of Thrones" averaged 13.6 million viewers with its premiere airing May 19, according to a network spokesman, citing Nielsen Holdings PLC data. That topped the 13.4 million for the fourth-season premiere of mob drama "The Sopranos" in 2002.

Tacking on viewership for replays and watching on authenticated platform HBO GO and stand-alone streaming service HBO NOW, the series finale tallied the largest ever first-night audience for the AT&T Inc.-owned network with 19.3 million watchers.

The final season has recorded five of the six most-watched episodes in the show's history.

Perhaps more impressive has been the overall audience marks. Adding viewing from digital video recording, on-demand platforms and additional replays, HBO said the show’s final season had averaged 44.2 million viewers ahead of the May 19 conclusion on a cumulative basis, up from 32.8 million for the seventh campaign.