For the first time someone has finished Diablo 3 on the hardest difficulty using a Hardcore character - just over a month after launch.
There may be spoilers ahead.
The Inferno difficulty is the hardest in the game - a significant step up from Hell. And the completion was done before the release of patch 1.0.3, which makes the game easier.
But the most impressive thing about this achievement is it was done using a Hardcore character. Hardcore characters are lost forever when they are killed. No going back.
Yesterday, on Tuesday 19th June, player Kripparrian, from Toronto, Canada, completed all four difficulties with a Hardcore Barbarian (with help from a Wizard called Krippi). And after initially casting doubt on the achievement's status as a world first, Blizzard community manager Bashiok put his official rubber stamp on it.
"My apologies Kripp and Krippi, looks like you were 1st HC Inferno clear," he tweeted. "(my spreadsheet deciphering isn't what it used to be) Congrats!"
A video showcasing the lengthy, tense Diablo kill - with explanation from Kripparrian - is below.