SAN DIEGO (AP) -- So much for the Kansas City Chiefs hoping that their season wouldn't get any uglier.
The Chiefs committed four more turnovers and lost their fifth straight game, 31-13 to the San Diego Chargers on Thursday night.
The Chiefs (1-7) have an NFL-high 29 turnovers, which have led to 104 points.
The horrendous lack of ball security could have coach Romeo Crennel worrying about his job security.
"Romeo told us before the game that we're going to have to eliminate the turnovers," said quarterback Matt Cassel, whose fumble and interception both led to a Chargers touchdown. "Until we eliminate the turnovers, we will have the same result. You can't turn the ball over in this league and expect to win."
The Chiefs still haven't led in regulation this season. Their only victory came when Ryan Succop kicked the winning field goal against the Saints in overtime.
"We had a 17-play drive at one point and didn't get anything out of it. Then in the fourth quarter, we were pressing and ended up with some negative plays," Crennel said. "We put ourselves in the position that we're in, and the only way we're going to get out of it is to fight our way out of it. It wasn't very good overall, but we're going to keep coaching and keep fighting and play our way out of it."
Antonio Gates caught a 14-yard yard scoring pass from Philip Rivers on the game's opening drive to snap San Diego's streak of six straight quarters without a touchdown.
Chargers coach Norv Turner should be able to breathe easier. He had been heavily criticized by fans after the Chargers (4-4) blew double-digit, second-half leads in losses to New Orleans and Denver, and then lost 7-6 at Cleveland on Sunday.
Still, at the start of halftime, some fans in one end zone unfurled a big yellow banner that read: "Mr. Spanos, please fire A.J. & Norv."
Team president Dean Spanos decided in January to bring back both Turner and general manager A.J. Smith even though the Chargers missed the playoffs for the second straight year.
Rivers, who looked shaky during the losing streak, did his part by completing 18 of 20 passes for 220 yards and two touchdowns, with one interception. Rivers also threw a 13-yard TD pass to Malcom Floyd early in the fourth quarter. Rivers' 90-percent completion rate tied for fifth-best in NFL history.
"We had a 17-play drive at one point and didn't get anything out of it. Then in the fourth quarter, we were pressing and ended up with some negative plays," Crennel said. "We put ourselves in the position that we're in, and the only way we're going to get out of it is to fight our way out of it. It wasn't very good overall, but we're going to keep coaching and keep fighting and play our way out of it.
With the Chiefs trailing 17-6, Cassel fumbled as he was sacked by San Diego's Jarret Johnson in the end zone and Shaun Phillips recovered for a touchdown early in the fourth quarter. On the next drive, Cassel's high pass deflected off Dexter McCluster's hands and was intercepted by Demorrio Williams, who returned it 59 yards for a touchdown.
Williams, who played for the Chiefs the last four seasons, forced a fumble in the first quarter.
The Chiefs had six turnovers in a 37-20 home loss to the Chargers on Sept. 30.
In just 2 minutes, 9 seconds, the Chargers' defense scored as many touchdowns as the offense has in 10 quarters.
Gates' first-quarter score was San Diego's first touchdown since the star tight end caught an 11-yard pass in the first half against Denver on Oct. 15. That score gave San Diego a 24-0 lead, but Peyton Manning rallied the Broncos to a 35-24 win.
The Chargers got only two field goals from Nick Novak in a 7-6 loss at Cleveland on Sunday, their third straight defeat.
After San Diego scored on the opening drive, Kansas City went on a 17-play drive, converting four third downs, but Dwayne Bowe fumbled after a 10-yard reception. Williams caused the fumble and Quentin Jammer recovered.
Bowe's fumble set up Novak's 25-yard field goal with 9:10 left in the second quarter.
After Kansas City decided not to go for it on fourth-and-1 from the San Diego 31, Succop kicked a 49-yard field goal with 2:51 left before halftime.
The Chargers had a third-and-goal from the 1 in the closing seconds of the half when Rivers was intercepted by Eric Berry.
Succop had a 41-yard field goal in the third quarter.
