Oct 13, 2013; Kansas City, MO, USA; Oakland Raiders wide receiver Denarius Moore (17) scores a touchdown against the Kansas City Chiefs in the first half at Arrowhead Stadium. Mandatory Credit: John Rieger-USA TODAY Sports

By Carey Gillam

KANSAS CITY, Missouri (Reuters) - Kansas City football fans were 'loud and proud' of their undefeated Chiefs on Sunday, cheering the home team to victory in a display of eardrum-splitting support that scored the loudest crowd roar on record at an open-air stadium, according to league officials.

A Guinness World Record official on site pegged the noise at Arrowhead Stadium in the fourth quarter at 137.5 decibels, as the Chiefs defeated the Oakland Raiders, the National Football League and Chiefs officials said.

The Chiefs won their sixth straight, remaining undefeated, as they took down Oakland 24-7.

"Every win is a great win. When you can win with a crowd like this, it makes it even better," Chiefs Head Coach Andy Reid said in a post-game news conference. "It was loud, I mean real loud. Ground-shaking loud."

The sold-out crowd shattered the stadium's previous noise level record of 116 decibels and broke past the previous world record of 136.6 decibels set by Seattle Seahawks football fans at home, according to officials.

The Seahawks had seized the title less than a month ago when they stole the record from fans of a Turkish soccer club.

"Congratulations. All records are meant to be broken," the Seattle Seahawks team tweeted the Chiefs.

Chiefs' fan and Kansas City-area resident Angela Klappa, who attended the game with her husband and friends, said she stomped, clapped and banged on the seats in front of her during the game.

"I have been going to Chiefs games for over 20 years and the fans have never been louder than they were today," Klappa said. "I have no voice after that game."

(Reporting by Carey Gillam; Editing by Dan Whitcomb and Philip Barbara)