Trailing 21-13 at halftime Thursday night against the Denver Broncos, some wondered if the Los Angeles Chargers had any resolve left after going through their worst four-quarter stretch of the season.

The Chargers put some doubts to rest getting back on track and getting closer to wrapping up a playoff spot.

Justin Herbert passed for 284 yards and two touchdowns, including a go-ahead 19-yarder to Derius Davis early in the fourth quarter, as the Chargers rallied for a 34-27 victory.

Los Angeles (9-6) have a 97% probability of making the playoffs with the win according to the NFL. They can wrap up their second postseason berth in three seasons Sunday with losses by Indianapolis and Miami.

“It was a total team effort by everyone. It was phenomenal,” coach Jim Harbaugh said. “The test and challenge is how you are going to respond. They went back to work and stayed the course.”

The Chargers’ comeback also included Cameron Dicker making the first successful fair-catch kick in the NFL in 48 years. He was good from 57 yards on the final play of the first half to pull the Chargers to 21-13.

Denver (9-6) could have clinched a playoff spot but had their four-game winning streak snapped. The Broncos still have an 85% chance of making it, but they have tough remaining tests at Cincinnati on 28 December and at home against Kansas City in Week 18.

“Obviously, a disappointing loss. There was a lot at stake, and we know that,” Denver coach Sean Payton said. “We had a fast start, and then uncharacteristically this season, we didn’t finish or play nearly well enough in the second half, both offensively and defensively.”

The Broncos appeared well on their way to wrapping up their first postseason berth since 2015 after they scored on their first three drives to go up 21-10. But after Wil Lutz’s 41-yard field goal midway through the third quarter gave the Broncos a 24-13 advantage, the Chargers stormed back.

“First three drives, 21 points, and then just kind of stalled,” said Bo Nix, who completed 29 of 40 passes for 263 yards and two touchdowns. “We got the same defense (in the second half). Just for whatever reason, we couldn’t get going.”

Gus Edwards – who had 14 carries for 68 yards – went off five yards off left end for his second touchdown of the game to get the Bolts within 24-19, but the two-point conversion was no good when Herbert was stopped short of the goal line.

Edwards also burrowed in from the 1 in the first quarter to tie it at 7.

After Denver went three-and-out for the second time in three possessions, the Chargers took their first lead. On first-and-10 from the Denver 19, Herbert – who completed 23 of 30 passes with an interception – scrambled left and threw across his body off his left foot to Davis with 12:29 remaining.

“We had him on a little bubble out of the backfield. I scrambled out, saw the pressure and he just turned upfield and made an incredible play,” Herbert said.

Herbert then found Joshua Palmer in the back of the end zone for the 2-point conversion. Palmer made a one-handed grab before going out of bounds to make it 27-24.

Los Angeles put it out of reach with 2:27 remaining on Herbert’s 34-yard touchdown pass to Hassan Haskins.

Lutz narrowly made a 55-yard field goal with 57 seconds remaining to get Denver within a touchdown, but Los Angeles’ Nick Niemann recovered the onside kick to dash any hopes of a comeback.

Herbert completed passes to 10 players, including Ladd McConkey, who had six receptions for 87 yards.

Nix had a pair of touchdown passes in the first half – a one-yard pass to Michael Burton off a rollout and a six-yard throw to Devaughn Vele in the left corner of the end zone – and completed 15 of 21 passes for 155 yards before halftime.

Audric Estime’s three-yard run off right guard gave the Broncos a 7-0 lead midway through the first quarter. It was only the third time this season Denver reached the end zone on their opening possession.

The Chargers were outscored 48-13 in four quarters that included the second half against Tampa Bay and first half against Denver.

Going into halftime, the defense had a stretch where it had allowed scores on 13 of 18 drives (including eight touchdowns) and forced only two punts in seven quarters.

Instead of Harbaugh addressing the team at halftime, it was safety Derwin James.

“I feel like, as players, we need to take it upon ourselves. This is our team too,” James said. “And I feel like, man, my message was simple. Man, it’s time for us to play ball. And I feel like, as a team, we just came out and did that. It was nothing rah, rah, rah. It was just, it’s time to go, man. It’s time for us to play our best ball in December, January. I feel like we did that today.”

Denver gained 212 yards on their first drive and 229 in the first half, but just 107 after halftime.

Coach Jim Harbaugh and the Chargers took advantage of a seldom-used fair-catch kick, which allows a team that has just made a fair catch to try a free kick for three points. The kick is attempted from the line of scrimmage, and the defending team must stand 10 yards away.

The Chargers were able to try it because Denver’s Tremon Smith committed fair-catch interference on what would have been the final play of the first half when Los Angeles’ Derius Davis attempted to field Riley Dixon’s punt at the Chargers 38.

The penalty moved the ball to the Denver 47 for an untimed down. The Chargers also were the last team to successfully execute a free kick when Ray Wersching converted from 45 yards for San Diego on 21 November 1976, against Buffalo.