SAN DIEGO >> Philip Rivers threw for 178 yards and one touchdown, passing Hall of Famer Dan Fouts to become San Diego’s career passing leader, and the Chargers held off the Denver Broncos 21-13 on Thursday night.

The victory may have saved embattled coach Mike McCoy’s job . The Chargers (2-4) were coming off a mistake-filled loss at Oakland, and earlier in the season lost three games in which they led at the 2-minute warning. There has been increasing fan discontent with the conservative McCoy, and the Chargers are trying to convince voters to approve a $1.1 billion public handout for a new downtown stadium in the form of an increase in the hotel occupancy tax.

The defending Super Bowl champion Broncos were coached by special teams coordinator Joe DeCamillis after Gary Kubiak was ordered by doctors to sit this one out because of a migraine condition that mimics strokes.

The five-time defending AFC West champion Broncos (4-2) were mostly sluggish behind Trevor Siemian, who was back at quarterback after rookie Paxton Lynch struggled in a loss to Atlanta. They lost their second straight game and had their NFL-record 15 straight divisional road victories snapped.

The Chargers snapped their streak of 10 straight divisional losses dating to 2014.

Rivers, in his 13th season with the Chargers and 11th as starter, has 43,094 career yards passing. Fouts threw for 43,040 yards in 15 seasons with the Bolts.

Rivers threw a 5-yard scoring pass to rookie tight end Hunter Henry to cap the game’s first possession. Rivers finished 18 of 29.

Otherwise, the Chargers had to settle for Lambo’s career-high four field goals, of 37, 21, 31 and 32 yards.

LATE-FIRING BRONCOS: Denver didn’t get across the 50 on its own accord until there were just 2 minutes left in the third quarter. Denver’s first score came after a punt bounced off San Diego’s Travis Benjamin and the Broncos recovered at the San Diego 11. The refs initially ruled that the Broncos downed the punt, but Denver challenged and got the ball. Brandon McManus kicked a 29-yard field goal.

Siemian was 30 of 50 for 230 yards, with a 5-yard scoring pass to Bennie Fowler midway through the fourth quarter.

McManus kicked a 46-yard field goal with 27 seconds left, and Denver recovered the onside kick at its 46. It got to the San Diego 45 with eight seconds to go before Siemian’s desperation pass was batted down by Dexter McCoil.

DEFENSIVE STAND: The Broncos were threatening at the San Diego 20 with less than 5 minutes to go. But on consecutive plays they were whistled for holding, Siemian was sacked by rookie Jatavis Brown and San Diego’s Craig Mager recovered a fumble by Demaryius Thomas.

RIVERBOAT MIKE: McCoy went for it on fourth-and-1 from the Denver 20 early in the second half, with Melvin Gordon going over the top for a 1-yard gain. Rivers misfired on two straight passes and was flushed on third down, forcing the Chargers to settle for Lambo’s 37-yard field goal for a 10-0 lead. McCoy improved to 25-31 overall in four seasons.

NEW HOLDER: Veteran backup quarterback Kellen Clemens took over as holder for the Chargers after rookie Drew Kaser’s misadventure at Oakland on Sunday. Kaser mishandled the snap on a potential tying field goal with 2:07 left in the 34-31 loss. Kaser, who also shanked a punt, kept his job as punter but lost his job as holder.

ANTHEM WATCH: Chargers players Joe Barksdale, D.J. Fluker, Chris Hairston, Joshua Perry and Tyreek Burwell held up their right fists during the national anthem.

INJURIES: Chargers rookie DE Joey Bosa was having his right hand worked on by the trainers after Denver’s first drive. He was back in for the next Broncos possession. … Broncos WR Cody Latimer left with a concussion in the second quarter. … Gordon limped off the field early in the fourth quarter. He had his right ankle taped and returned on San Diego’s next possession.