ORCHARD PARK, N.Y. -- The Kansas City Chiefs are no longer unbeaten, but they didn't seem much bothered by that, least of all quarterback Patrick Mahomes.

"The undefeated thing was cool," Mahomes said after the Chiefs took their first loss of the season 30-21 against the Buffalo Bills on Sunday. "But that's not our ultimate goal."

The Chiefs won their first nine games but were hardly dominant along the way. Seven of those victories were by one score, and four were not settled until the game's final play.

The loss to the Bills was different and not just in the result. The Bills clearly outplayed the Chiefs, outgaining them by more than 100 yards. The Chiefs led only twice in the game, both times in the first half. But each lead was brief and by just one point.

Mahomes called the loss "fuel" for the rest of the Chiefs' season.

"It's a good football team, so there's nothing to hang your head [about]," Mahomes said. "We feel like we can play better, so we will get back to work and try to use this as a spark so that we can be a better football team in the end.

"I'm hoping that [losing] is a benefit. I'm not going to say I or we relaxed, but at the same time I feel like we were just coming away with these wins at the end of the game. I think it's going to spark us to have more urgency, especially at the start of football games, especially with the offense, and that comes from me and turning the ball over on the first drive. It's something you can't do in big games like this."

The Chiefs had won 15 straight games dating back to last season, including the playoffs. Their last loss came on Christmas of last season when they were beaten by the Las Vegas Raiders. Mahomes said he saw no similarities to Sunday's loss but hoped this defeat would also bring a new long winning streak.

"[The Bills are] a really good football team," he said. "It's going to take your best football to beat great football teams, and we didn't play our best football today and they went out there and beat us. That's how it rolls in the NFL and so all due respect to them that's going to be a good football team that we will probably see [in the playoffs]."

Mahomes was outplayed by Josh Allen, his Buffalo counterpart. Cornerback Trent McDuffie said there were times the Chiefs defended Allen as they intended and still couldn't prevent him from making plays.

"He's one of those people where no matter what happens, he can make his team right," McDuffie said.

Most notable among those plays was Allen's 26-yard touchdown run late in the game that secured the win. A fourth-down stop on that play would have left the Chiefs with two minutes to try for a winning field goal.

"That was a great football play," Mahomes said. "Whenever the play's not there, he does a great job of making plays happen, and that's what he did on that last play."