'Game of Thrones'

Emilia Clarke in HBO's fantasy hit "Game of Thrones." (HBO / April 7, 2014)

HBO has spent years looking for another hit like "The Sopranos," and it may have found it in "Game of Thrones."

Season 4 of the epic fantasy opened at 9 p.m. Sunday night averaging 6.6 million total viewers, according to Nielsen.

Those are the best numbers for HBO since 2007, when the mob drama "Sopranos" ended with 11.9 million viewers.

PREMIERE: Season 4 recap of 'Game of Thrones'

It's also a huge bump over the 4.4 million viewers for the season 3 premiere in 2013. "GoT" premiered in 2011 with a relatively modest 2.2 million viewers and has steadily grown its audience since.

In fact, the popularity of "Game of Thrones" caused a glitch Sunday. HBO Go, the network's streaming service, crashed due to heavy demand.

At 10 p.m., HBO premiered "Silicon Valley," a new comedy satirizing the tech industry. It averaged 2 million total viewers -- the best showing for a new HBO half-hour in nearly five years.

What did you think of the "Game of Thrones" premiere?

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