Critics and fans were outraged over the penultimate episode of Game of Thrones, calling it a "colossal mistake" on par with the derided How I Met Your Mother finale. But despite the post-air backlash, it's likely executives at HBO are happy with how things played out. "The Bells," the fifth episode of Thrones' six-episode final season, has become the highest-rated episode in the show's history.

Game of Thrones Didn't Come Close to Earning Dany's Mad Queen Moment

According to HBO, a record 18.4 million viewers tuned in to watch "The Bells" via HBO's various platforms (cable, HBO GO, and HBO NOW). That number breaks the previous viewership record, set this season when 17.8 million people watched "The Long Night." It's also the third rating record set by Thrones during its final season: the season premiere was watched by 17.4 million people, which was a then-record for the series.

Overall, the final season of Game of Thrones is averaging 43 million viewers per episode across total gross audience, according to HBO, a number which marks an increase of 10 million viewers from Season 7.

Game of Thrones Season 8 Spoilers | "The Bells" review

It's likely everything above will be moot by this time next week, as the Game of Thrones finale is poised to break this record and close out the series with its highest numbers ever.

In the penultimate episode, fans were shocked and dismayed after Daenerys Targaryen (Emilia Clarke) made a heel turn into the Mad Queen and brutally killed thousands of innocent civilians inside the gates of King's Landing. The episode included a high body count as well, offing Cersei Lannister (Lena Headey), Jaime Lannister (Nikolaj Coster-Waldau), Euron Greyjoy (Pilou Asbaek), and Varys (Conleth Hill), among others.

Game of Thrones' series finale airs Sunday, May 19 at 9/8c on HBO.

Need HBO? Add it through Hulu or through Amazon.