Plays that defined the season: Justin Houston's 21st sack

KANSAS CITY, Mo. -- Here is the last in a series of 10 plays that shaped the Kansas City Chiefs' 2014 season. We're going in chronological order, not in order of importance.

Linebacker Justin Houston entered the season's final game on Dec. 28 against the San Diego Chargers at Arrowhead Stadium with 18 sacks, two behind the Chiefs' season record of 20 set by Derrick Thomas in 1990.

He tied the record with two sacks in the first half. In the third quarter, Houston bull-rushed San Diego tackle D.J. Fluker, pushing him close enough to quarterback Philip Rivers to where Houston could not only tackle Rivers but also knock the ball loose.

The Chiefs recovered and would kick a field goal that would give them a 19-7 lead. That was also be the game's final score.

Houston would go on to get one more sack late in the game, allowing him to finish the season with 22. That was a half-sack from the NFL record of 22.5 set by Michael Strahan of the New York Giants in 2001.

Houston finished one of the greatest individual defensive seasons in Chiefs' history with a flourish. The four sacks of Rivers were a season-high but Houston didn't build his season off one spectacular game. He was an every-down presence for the Chiefs as a pass-rusher, when he dropped into coverage or defended the run.

Houston had at least one sack in 13 of the Chiefs' 16 games.