Philip Robertson, a Guinness adjudicator, said the crowd of 76,394 people at ArrowHead Stadium for Sunday's game reached 137.5 decibels, beating the 136.6-decibel record for "loudest crowd roar at a sports stadium" set by Seattle Seahawks fans Sept. 15, The Kansas City (Mo.) Star reported Monday.
Robertson said the record-setting roar came from the crowd during the final seconds of the Chiefs' 27-7 victory over the Raiders.
"I think the fans saw something on the flashboard [scoreboard]. ... It was that high-pitched scream that pushed them over the edge. And then we have a Guinness World Record," Robertson said. "It was just so unexpected, that last 30 seconds. It was almost like a dramatic Hollywood finish to a football game."