Off to their best start in five years, the AFC West-leading Kansas City Chiefs don't want to get too excited about their early season success. But a matchup with the winless Buffalo Bills could give them even more confidence before back-to-back division road games.

Kansas City looks to open with four straight home wins for the first time since 2003 when it faces a Bills team trying to avoid its worst start in 26 years Sunday.

The Chiefs sit atop the division at 4-2, but with the regular season not even halfway complete and visits to Oakland and Denver looming, they understand there is still plenty of work in front of them.

"It's still really early in the season," running back Thomas Jones said. "We've only played six games. We've got a long way to go. We're just trying to build off some of the things we've done positively.

"We have a lot to improve on. Whether you win or lose, you have to forget about it and move to the next week. Guys are already watching Buffalo film and getting a game plan together."

That plan will likely be a heavy dose of Jones and Jamaal Charles, who power the NFL's top-ranked rushing attack at 176.5 yards per game. The Chiefs ran for a season-best 236 in last Sunday's 42-20 victory over Jacksonville, with Jones going for a season-high 125 on 20 carries.

Looking to rush for 200-plus yards in three straight games for the first time since Sept. 3-17, 1978, the Chiefs will line up opposite a Bills run defense ranked last in the NFL at 174.5 yards allowed per game.

Switching to a 4-3 defense following its bye week, Buffalo gave up 125 rushing yards in last Sunday's 37-34 overtime loss in Baltimore after yielding 200-plus in each of its previous three games.

The 0-6 Bills, who have the second-fewest sacks in the AFC with eight and a league-worst one interception, have allowed 30 points or more in a franchise-record five consecutive games.

"Come on, man, it's something we're not satisfied with," defensive end Marcus Stroud said. "We're working, we're trying to get better every week. We gave up points, point blank."

Buffalo could be tested by Chiefs quarterback Matt Cassel and an offense that has thrived in its first season under coordinator Charlie Weis.

Kansas City, which rolled up 426 yards against the Jaguars, already has more 30-point games this season (three) than in any since 2006.

With Cassel managing the offense, the Chiefs are tied with the New York Jets for the league lead with four turnovers.

"Offense is an 11-man operation, running and passing," coach Todd Haley said following last weekend's win. "I thought we were pretty efficient as an offense. We didn't turn the ball over."

Bills coach Chan Gailey wish he could have said that after the Ravens loss. Despite Ryan Fitzpatrick throwing for a career-best 374 yards and an NFL season high-tying four touchdowns, Buffalo committed a season-worst four turnovers, with the final one setting up Baltimore's winning field goal.

"It's hard to win when you turn it over four times," said Gailey, whose team is one loss shy of its worst start since opening 0-11 in 1984. "I think we took a step forward in some respects. But we didn't play smart in some areas."

Fitzpatrick has thrown at least two TDs in each of the last four games and has big-play targets in Lee Evans (career high-tying three TDs last week) and Steve Johnson (five TDs in the last four games). The former Harvard standout, though, is smart enough to realize that success in the NFL is only based on wins and losses.

"We're still searching for that first win," Fitzpatrick said. "I can tell you that ... we're going to get over the hump."

Buffalo, which has lost its last two road games by 11 combined points, has won two straight at Arrowhead Stadium and three in a row overall in this matchup. Fred Jackson rushed for 99 yards on 20 carries, while Fitzpatrick completed 12 of 20 passes for 86 yards in a 16-10 victory in Kansas City on Dec. 13.

Charles ran for 143 yards and a TD in that defeat, and Cassel was sacked three times while throwing a career-high four INTs -- three in the fourth quarter.

Chiefs wide receiver Dwayne Bowe has two TDs in each of the last two games to give him five on the season. He had four touchdown receptions in 11 games in 2009.