DENVER -- Linebacker Justin Houston, in only his second game of the season, is having an outsized impact for the Kansas City Chiefs in Sunday night's game against the Denver Broncos.

The Chiefs lead 9-3 at halftime.

Houston has three sacks, and one caused a fumble by Broncos quarterback Trevor Siemian that led to the game's first points. Houston split two blockers to sack Siemian, and the Broncos recovered the loose ball in their own end zone for the safety.

The Chiefs scored on the subsequent kickoff when Tyreek Hill returned it 86 yards for a touchdown.

Houston left the game late in the first half with a shoulder injury. He went to the locker room shortly before halftime but returned to the lineup for Denver's last drive of the half.

Houston played his first game of the season last week against the Tampa Bay Buccaneers after having offseason surgery to repair a balky ACL in his left knee.