ORCHARD PARK, N.Y. -- J.P. Losman discovered something about himself while he spent the last month stewing on the sideline.
The angrier he is, the better he plays.
Stepping in after Holcomb sustained a concussion in the second quarter, Losman engineered scoring drives on two of his first four possessions, showing he's ready to reclaim his old job.
"I like playing mad. I like playing upset," Losman said. "I feel like it was a comeback for me. Whether I played good or bad, I loved the way I focused. I loved the way I was concentrating. I loved that anger."
Losman finished 9-of-16 for 137 yards, hitting Lee Evans for both touchdowns. Losman was focused and efficient, looking nothing like the hesitant first-year starter who went 1-3 before being replaced by Holcomb following a 19-7 loss to New Orleans on Oct. 2.
The Bills (4-5), coming off their bye week, snapped a two-game losing streak and won with a defense further depleted by injuries.
The Bills generated three interceptions, a fumble and six sacks. Kansas City's three points were the fewest Buffalo has allowed since beating New England 31-0 in the 2003 season opener.
Kansas City (5-4) lost its fifth straight game at Buffalo, and failed to build off a last-second 27-23 win over Oakland last weekend.
Trent Green was uncharacteristically sloppy, going 23-of-40 for 220 yards and three interceptions -- after throwing three in his previous eight games. His 41.7 passer rating was his worst since a 35.5 against the New York Jets in 2001.
"It's very frustrating," Green said. "We had too many turnovers and they played very good bend-but-don't-break defense. They had two big plays and we didn't have any."
Kansas City lost despite generating more yards (316 to Buffalo's 209), more first downs (22-9) and controlling the ball for nearly 35 minutes.
The problem was how the Chiefs persistently squandered opportunities.
Of seven drives into Buffalo territory, Kansas City mustered Lawrence Tynes' 35-yard field goal that opened the scoring.
The other six drives ended with two punts, two missed field goals, a fumble and giving the ball up on downs.
"Even though you control the ball for 10 minutes more and make more yards, it doesn't matter," Chiefs coach Dick Vermeil said. "You have to score points. It's disappointing to come up here and not play better."
Defensive end Jared Allen put the loss on the defense.
"We should have won the game 3-0," Allen said. "For two plays they were better than us. And that was the deciding factor."
The Bills defense wasn't going to let this one get away.
"They came in and tried to take over our house and we weren't going to let it happen," said linebacker London Fletcher, who led the team with 20 tackles.
Linebacker Jeff Posey noted Losman's play.
"To be able to come in when his number is called, that says a lot about the guy," Posey said. "It tells you what kind of character, what kind of guy he is."
Losman's first touchdown pass -- a 33-yarder to Evans -- came on his first series. His second touchdown pass, coming midway through the third quarter, was his best throw. He hit Evans with a perfectly placed pass over the receiver's right shoulder, in stride and a step ahead of Eric Warfield.
"That just came with having a lot of pocket poise and just trusting and throwing," Evans said, referring to Losman. "I think he's got a lot more confidence."
- Tight end Tony Gonzalez had eight catches for 81 yards, giving him 7,362 for his career, passing Otis Taylor to become the team's all-time leading receiver.
- J.P. Losman finished with a career-high 124.2 passer rating.
- Lawrence Tynes had his streak of consecutive field goals end at 14 when he was wide right from 44 yards.
- Chiefs RG Will Shields became only the fourth non-kicker since the AFL-NFL merger in 1970 to start 200 consecutive games.
- Bills K Rian Lindell missed two field goal attempts, including a 28-yarder wide left.