Harrison Butker kicked a 43-yard field goal in the final seconds of his first career game, and the Chiefs remained undefeated by beating the Washington Redskins, 29-20, in Kansas City on Monday night.

Chiefs' defender Justin Houston returned a fumbled Washington lateral 13 yards for a touchdown to end the game, tacking six points on to the final score.

Behind a solid passing night from Kirk Cousins, the Redskins led 10-7 at halftime and 17-14 late in the third quarter. Kansas City (4-0) tied the game at 17 on Butker's first career field goal -- a 26-yarder at the end of the third quarter. He was signed off the Carolina Panthers' practice squad last Tuesday to replace the injured Cairo Santos.

A 32-yard field goal from Butker put the Chiefs ahead in the final quarter, but Cousins led his team back into scoring position late. Dustin Hopkins' 40-yard field goal with under a minute to play tied the game at 20 for Washington (2-2).

Cousins finished 14-for-24 for 220 yards and two touchdowns. He also ran for 38 yards, including two long scampers on his team's final drive.

Alex Smith threw for 293 yards and a touchdown to Travis Kelce, who caught seven passes for 111 yards for Kansas City. Kareem Hunt added 101 yards rushing for the NFL's last unbeaten team.