Buffalo Bills' defense found its secret weapon in Week 9 win over Chiefs

For weeks, Sean McDermott has emphasized the Buffalo Bills’ need for their pass rush and coverage to work together in order to impact opposing quarterbacks.

Far too often this season, one element or the other has not lived up to its end of the bargain defensively, leading to their opponents’ signal callers having far too much time in the pocket, producing many connections deep down the field.

Well, during Buffalo’s Week 9 win over the Kansas City Chiefs, McDermott got his wish, with all three levels of the Bills’ defense playing together on a string to help limit Patrick Mahomes to the worst passing performance of his career.

“The D-line led us,” said the Bills' head coach postgame. “We were able to do some things with rush and coverage working together, which was good to see, and affect the quarterback.”

Nov 2, 2025; Orchard Park, New York, USA; Buffalo Bills defensive end Joey Bosa (97) pressures Kansas City Chiefs quarterback Patrick Mahomes (15) in the second half at Highmark Stadium. | Gregory Fisher-Imagn Images

The Buffalo pass rush was at the forefront of the team’s success, recording three sacks and 15 quarterback hits to spearhead a historic performance against the Chiefs’ quarterback. Mahomes completed just 15 of 34 passes, which equated to a completion percentage of 44%, the lowest mark of his career and the first time the former MVP has ever completed fewer than half of his attempts in a game.

“Patrick is a once-in-a-lifetime player and so difficult to beat," added McDermott. "When he stands back there and he’s not affected, it's for the type of quarterback, it’s almost 7 on 7. So the rush and coverage did a really good job tonight, and it started by winning early downs so we could get him in some of those third-and-longs.”

According to Next Gen Stats, the Bills pressured Mahomes on 20 of his 38 dropbacks, which was the first time the Chiefs QB faced pressure on a majority of his dropbacks since Week 5 of the 2020 season. That pressure led to Mahomes holding onto the ball far longer than he has been accustomed this season, resulting in him being sacked three times.

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Buffalo Bills defensive end Joey Bosa sacks Kansas City Chiefs quarterback Patrick Mahomes with linebacker Terrel Bernard coming in to help during first half action against the Kansas City Chiefs at Highmark Stadium in Orchard Park on Nov. 2, 2025. | Tina MacIntyre-Yee/Democrat and Chronicle / USA TODAY NETWORK via Imagn Images

Entering Sunday’s game, Mahomes’ average time to throw of 2.61 seconds was the quickest in the league. But against the Bills, his average time to throw was 3.37 seconds, which was his longest time to throw in a game over the last two seasons.

The Bills’ pressure rate of 52.6% against Kansas City was their highest across 10 matchups with the Chiefs since the 2020 season, with veteran edge rushers Joey Bosa and Greg Rousseau powering a ferocious effort from Buffalo’s defensive front. Bosa finished with a sack, two tackles for loss and five quarterback hits, while Rousseau put forth a career performance.

“It feels good,” said Bosa. “Just proud of everybody. The way we rushed, kept them in the pocket, affected them. Just couldn’t be happier right now.”

Rousseau generated nine pressures and a shared sack on 28 pass rushes, per Next Gen Stats, which was his most pressures in a game this season and the third-most of his career. It was a slow start for Rousseau, but he has quickly rounded into form over the past few weeks, recording at least a half-sack in three of the Bills’ last four games. He now has three sacks on the season.

“We wanted to keep (Mahomes) in the pocket,” said edge rusher A.J. Epenesa, who finished with two QB hits, including a massive blow on the Chiefs’ QB near the sideline. “I think the guys did a really good job of just being really disciplined today and just doing their 1/11th.”

The loss of Michael Hoecht stings, but with Bosa and Rousseau starting to play their best football, and Epenesa continuing to surprise, this unit is one to fear moving forward.

Finally, General Manager Brandon Beane has supplied the Buffalo defense with a reasonably impactful pass-rushing group that strikes fear in opponents. As the secondary continues to smooth things out, the Bills’ talent up front will help supplement any potential changes that may be coming to the Buffalo secondary in the near future.

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