HBO's "House of the Dragon" has already been greenlit for season 2.

After 9.99 million viewers tuned in for Sunday's series premiere across HBO and HBO Max — the largest audience for a series premiere in the pay TV channel’s history — Warner Bros. Discovery (WBD) confirmed to Yahoo Finance that a new season is already in the works with viewership for the "Game of Thrones" prequel now swelling to 20 million since Sunday.

"We are beyond proud of what the entire ‘House of the Dragon’ team has accomplished with season one," Francesca Orsi, executive vice president of HBO Programming, said in a statement.

"Our phenomenal cast and crew undertook a massive challenge and exceeded all expectations, delivering a show that has already established itself as must-see-TV. A huge thank you to George, Ryan, and Miguel for leading us on this journey. We couldn’t be more excited to continue bringing to life the epic saga of House Targaryen with season two."

"House of the Dragon" — which reportedly cost between $15 million to $20 million per episode — is the first major franchise to arrive under the newly formed Warner Bros. Discovery company. Reviews have so far been positive, with the series receiving a critic score of 83% and an audience score of 86% on Rotten Tomatoes as of Friday morning.

The quick renewal underscores the platform's commitment to the series, both from a content and financial perspective. HBO reportedly spent over $100 million on just the marketing for the series, the biggest marketing campaign ever for HBO and on par with the media spend of most theatrical tentpoles.

Warner Bros. Discovery, meanwhile, is still working to aggressively cut costs, as the company eliminated 14% of its HBO Max workforce last week after announcing the streaming service will combine with Discovery+ in one platform, set to launch next summer.

Alexandra is a Senior Entertainment and Food Reporter at Yahoo Finance. Follow her on Twitter @alliecanal8193 and email her at [email protected]

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