ORCHARD PARK, N.Y. -- It was a day of many happy returns for the Kansas City defense as the Chiefs stormed back to defeat the Buffalo Bills 23-13 and remain the NFL's only unbeaten team Sunday afternoon at Ralph Wilson Stadium.
The Bills, with fourth-string, rookie quarterback Jeff Tuel making his first start, were driving for a score that would have given them a 17-3 lead early in the third quarter when cornerback Sean Smith intercepted a pass at the goal line and returned it 100 yards. Then, early in the fourth quarter, cornerback Marcus Cooper stripped the ball from Bills receiver T.J. Graham, and linebacker Tamba Hali picked it up and ran it in from the 11 to give Kansas City a lead it wouldn't relinquish.
Coach Andy Reid's opportunistic Chiefs had three takeaways that resulted in 17 points as they improved to 9-0 for the first time in 10 years.
The Bills lost for the fourth time in five games and dropped to 3-6.
Buffalo rushed for 229 yards and out-gained the Chiefs, 470 to 210. But they couldn't make up for the turnovers, especially Smith's coast-to-coast pick-6.
"No way was I going to let anybody catch me on that one,'' said Smith, a fifth-year veteran out of Utah. "When I caught that ball, I saw a lot of open space. The quarterback was the only guy really who had a shot at me and I wasn't about to let a quarterback catch me. I'd never have heard the end of it."
Tuel, filling in for injured starter EJ Manuel and injured backups Thad Lewis and Kevin Kolb, took full blame for interception.
"It was 100 percent my fault; it's something I've got to see,'' said Tuel, an undrafted rookie who was 18 of 39 for 229 yards and one score and was intercepted twice. "We've got to finish with a kick no matter what -- whether it's an extra point off a touchdown or a field goal. It's 100 percent on me."
Running back Jamaal Charles once again was the focal point of the Kansas City offense with 90 yards rushing on 17 carries and six receptions for six yards. Quarterback Alex Smith finished 19 of 29 for 124 yards and no scores.
Bills running back C.J. Spiller, back after missing last week's game with a high ankle sprain, had his best game of the season, rushing for 116 yards on 12 carries and catching two passes for 39 yards. Teammate Fred Jackson chipped in with 77 yards on 16 carries and 22 yards on one catch.
The Bills took a 7-0 lead with 1:52 left in the first quarter when Tuel lofted a 59-yard touchdown pass to rookie speedster Marquise Goodwin.
Kansas City closed the gap to four points midway through the second quarter on Ryan Succop's 27-yard field goal. The score was set up by Kendrick Lewis' interception on a Tuel overthrow at the Bills' 41.
Buffalo went up 10-7 on Dan Carpenter's 26-yard field goal with 1:47 left in the half. The score capped a 10-play, 71-yard drive that was fueled by a 29-yard run by C.J. Spiller to the Chiefs' 16.
It appeared the Bills were going to take control of the game after Spiller's 61-yard run to the Kansas City 19. But six plays later, on a third-and-goal from the 1, Smith intercepted the ball at the goal line and went the distance to tie the score at 10 with 10:58 left in the third quarter.
Succop's 41-yard field goal with 3:57 left in the third gave the Chiefs their first lead of the game.
A 20-yard pass from Alex Smith to Anthony Fassano and a 12-yard run by Charles were key plays in the drive.
The Bills knotted it at 13 on Carpenter's 30-yard field goal with 20 seconds remaining in the third. Spiller took a short pass from Tuel 27 yards to the Chiefs 25 during the drive.
Kansas City regained the lead when Hali scored on Graham's fumble.
Succop closed out the scoring with a 39-yard field goal with 2:13 remaining.
"I don't know what it is about this football team and second halves, but as long as they keep resulting in victories, we'll take it,'' Smith said. "These aren't beauty contests; they're football games. As long as we've got more on our side of the scoreboard, that's cool.
NOTES: This was the ninth consecutive game in which the Chiefs held an opponent to 17 points or fewer . . . Buffalo's Leodis McKelvin returned a punt 89 yards for a touchdown early in the first quarter, but the score was negated by an illegal block to the back penalty against Nigel Bradham. ... For the first time since 1968, the Bills have used three different starting quarterbacks through nine games -- Manuel, Lewis and now, Tuel. That year, five quarterbacks started regular-season games for them.