Philip Rivers threw four touchdown passes, three of them after halftime.Philip Rivers and the San Diego Chargers turned things around dramatically after halftime in their comeback victory over the San Francisco 49ers.

In Saturday night’s game, the Chargers overcame a 21-point deficit for the second time in franchise history, the first time since a 49-41 victory over the Cincinnati Bengals in Week 10 of 2006. A big reason behind the rally was Rivers’ performance in the second half.

Rivers finished with four touchdown passes, tying his career high. It was his sixth career game with four passing touchdowns, his first since 2013 Week 1. Three of those touchdown passes came after halftime.

In the first half, Rivers had as many interceptions as completions (two) on throws more than five yards downfield. In the second half and overtime, Rivers completed seven passes at least 15 yards downfield, matching his most in a game this season. He was 5-of-5 after halftime when targeting Antonio Gates.

Philip Rivers Passing More Than 5 Yds Downfield Saturday

The Chargers converted two fourth-down plays – a fourth-and-8 and a fourth-and-10 – on their game-tying drive late in the fourth quarter. Across the NFL this season, teams have converted 17 percent (about 1 in 6) of fourth-quarter fourth downs when they have faced eight or more yards to go for a first down. Those two conversions made the Chargers 3-for-3 on fourth down in the game; they were 1-for-5 on fourth down this season before Saturday.

49ers rely on the run

The rushing game carried the 49ers’ offense. They totaled 355 yards on the ground, the most by the team since 1948 and third-most in franchise history. The 49ers became the first team to rush for 300 yards and lose since the Kansas City Chiefs lost to the Indianapolis Colts in Week 16 of 2012 despite rushing for 352 yards.

The highlight play of the 49ers’ rush game was Colin Kaepernick’s 90-yard touchdown run late in the third quarter, which helped restore the 49ers to a 14-point lead, 35-21, after the Chargers had closed to seven by outscoring the 49ers 14-0 coming out of halftime.

Kaepernick’s run was noteworthy on a couple of fronts. It was the second-longest run by a quarterback since 2001. Only Terrelle Pryor’s 93-yard run in Week 8 of 2013 against the Steelers – on the first snap of the game – is longer than Kaepernick’s in that time. In 49ers history, Kaepernick’s run was the second-longest rush touchdown, behind a 96-yard scoring run by running back Garrison Hearst in 1998.

Two 100-yard rushers a rarity

The 49ers’ Frank Gore totaled 158 yards on the ground, including 93 after contact – his most after contact since 2008. Gore and Kaepernick became the first 49ers duo to each top 100 rushing yards in a game since Nov. 13, 1977 (Wilbur Jackson and Delvin Williams).

The 49ers were especially effective between the tackles. Their 243 yards inside the tackles were their most since 2008.

The Chargers allowed more than 300 rush yards in one game for the first time since they allowed 378 against the Vikings in Week 9 of 2007. That game was memorable because Adrian Peterson set the NFL single-game rushing record with 296 yards.

As rare as the Chargers’ rally was, the 49ers’ collapse was more so. They had lost only one game when leading by 21 or more points: 42-41 to the Vikings on Oct. 24, 1961. San Francisco led 35-14 at halftime of that game.