An American team of professional video gamers took home nearly $7 million after winning the world's biggest eSports tournament

In an hours-long match at KeyArena in Seattle, Wa. on Saturday, American eSports team "Evil Geniuses" beat out "CDEC" to take first place at The International ("TI5").

Evil Geniuses took home $6.6 million of the tournament's overall $18,416,970 prize pool.

The nearly five hours of grand finale play are right here if you've got a spare half-day:

The International is an annual tournament for eSports game "DOTA 2," held by the game's creator Valve Software. It consistently draws sold-out crowds to massive arena. It started in 2011 with the launch of "DOTA 2," and took place in Cologne, Germany during annual gaming conference Gamescom. The International 2015 is the fifth year that the tournament has been held, and its prize pool is the largest of any eSports tournament ever held.

The full pool is $18,416,970, the vast majority of which is contributed by fans. Valve itself contributes a base pool of $1.6 million, while the rest of pool comes from "Compendium" sales - an interactive community game that doles out rewards to "DOTA 2" players based on how high the cumulative pool gets. This year, the community raised $16,816,970 - a staggering number, which pushed the full pool just shy of $20 million. 

Here's a look at the prize pool's growth over time: 

It's not a winner takes all event, though, as the second, third, and fourth place teams take home a pretty decent chunk of cash. Here's the breakdown of the prize pool:

Of the five years the event has been held, an American team has never taken first place.

And Evil Geniuses is a good fit for first winner. The team name has been in use in competitive gaming since the 1990s. The company was originally founded in Canada with one team, a "Counter-Strike" competitive team (a first-person shooter game also developed by Valve Software), and later relocated to San Francisco. 

The team had never placed in the winner's bracket previously, nor had the runner-up CDEC (which took home $2.85 million). 

The International 2015 finals were attended on Saturday by a sold-out crowd of thousands. Later in August, another crowd of thousands will attend the "League of Legends" summer finals at Madison Square Garden in New York City. Both "DOTA 2" and "League of Legends" are played by tens of millions, and both represent the "Massive Online Battle Arena" genre (MOBAs) - there's a lot of crossover between the two games. 

For more on the eSports phenomenon, don't miss Tech Insider's new series "League of Millions" - here's the first episode: