Context: The Broncos traveled to Cleveland Browns Stadium to face the Cleveland Browns in what would again be a primarily defensive struggle. The Broncos again had a 100-yard rusher in Tatum Bell, with 115 yards (and also 1 touchdown), and also had a 100-yard receiver in Javon Walker, with 107 yards. Former Bronco Reuben Droughns was held to just 33 yards rushing and 27 yards receiving (60 yards total). Jake Plummer again struggled, throwing 1 touchdown (to rookie Brandon Marshall, the first of his career), but also 2 interceptions. Although Denver committed 2 turnovers, they also forced three; one interception (by Champ Bailey, making it three consecutive games with an interception) and two fumbles. After Jake Plummer threw his second interception of the day in their own red zone, the Browns scored their only points when Charlie Frye threw a touchdown pass to Joe Jurevicius in the fourth quarter, only the second touchdown allowed by the Broncos all year. It also ended their second 11-quarter streak without a touchdown allowed of the season. Denver at the time had only allowed 44 points all season, the lowest in the league. However, in one of the few items of bad news for the Broncos, left tackle Matt Lepsis suffered a season-ending knee injury. Also, kicker Jason Elam missed just his second field goal of the season in the third quarter. After the Chargers lost to division rival Kansas CIty, the Broncos took over the AFC West with a 5-1 record.

Question: Which team lost for the Broncos to take over the AFC West?

Answer:
Chargers