Riot Games has raised $8 million in funding from Benchmark Capital, FirstMark Capital, and Chinese online media company Tencent. Tencent is a new investor; it recently signed a deal to distribute Riot Games’ forthcoming multi-player online game, League of Legends, in China. Benchmark and FirstMark backed the L.A.-based startup with a $7 million round last year.

League of Legends (pictured) is slated for a North American launch this fall; the free-to-play game is monetized through micro-transactions, a business model that has proven to be extremely lucrative for Tencent.

In an interview with Gamasutra, Riot Games President Marc Merrill said Tencent’s involvement has bolstered the studio’s faith in the viability of virtual goods and micro-payments as a sustainable way to fund a game that will constantly need upgrades and enhancements.

Tencent is also evolving into the partner-of-choice for U.S.-based gaming companies that want to crack the Chinese market, as Take-Two (NSDQ: TTWO) recently teamed up with the company to launch its NBA 2K sports franchise in China. Release.

• Riot Games Secures $7 Million From Benchmark Capital And FirstMark Capital
• Take-Two Brings NBA Game To China, Launches 2K Online With Tencent
• How One Social Net In China Is Making A Lot Of Money