But the players in the home jerseys did not despair. The Chargers figured the second half could only get better, and thanks to an aerial attack that was reminiscent of the glory days of Dan Fouts, it did.  Philip Rivers, the Chargers’ fourth-year quarterback, completed six passes of more than 18 yards in the final 30 minutes, including a 25-yard go-ahead touchdown pass to Vincent Jackson in the third quarter, to lead the Chargers to a 17-6 victory.  “We have that type of big-play ability, and we’re probably going to be needing it the rest of the way,” Rivers said.  The Chargers will play the Colts, the defending Super Bowl champions, on Sunday afternoon in Indianapolis.  Jackson finished with 5 catches for 114 yards, nearly keeping pace with teammate Chris Chambers, who led all players with 6 catches for 121 yards.  “There were some zones and some holes in there, and we were able to exploit that,” said Jackson, who had his first 100-yard game of the season.  The receivers were thrust into starring roles because the Titans successfully contained running back LaDainian Tomlinson, who was held to 42 yards on 21 carries.  Tomlinson scored in the fourth quarter on a 1-yard run, but it was Rivers’s arm that roused the Qualcomm Stadium crowd, which had sat wet and miserable through a sloppy first half. The enthusiasm of the tailgaters before the game seemed tepid, like the cups of hot cocoa that some held in their gloved hands.  The rain that fell intermittently all day was not entirely to blame. A cold front always seems to blow through the stadium this time of year. The Chargers had not won a playoff game since January 1995. They entered the playoffs as the American Football Conference West champions for the third time in four years, but that title carried all the luster of a flashy rim on a flat tire. Last season, they were 14-2 and the A.F.C.’s top seed, but they lost to the Patriots in their playoff opener.  The Titans arrived here more dinged up than a jalopy. Quarterback Vince Young’s two favorite targets — Roydell Williams and Bo Scaife — who had 101 catches between them, were out with injuries, as were center Kevin Mawae and right guard Benji Olson.  Young started despite nursing a sore right quadriceps. He showed no ill effects on the Titans’ first drive, rising above the clamor of the crowd to lead a 13-play, 61-yard drive that culminated in a 30-yard field goal by Rob Bironas.  The Chargers had ridden Tomlinson down the stretch. In the last six games of the regular season, all victories, Tomlinson averaged 113.2 yards rushing to finish with a league-leading 1,474. But running in a steady drizzle, Tomlinson spent the first half spinning his wheels. He would gain 3 yards on one carry and lose 3 on the next, and at halftime, all he had to show for his effort was 6 yards on 7 carries.  The Titans’ LenDale White fared better, rushing for 61 of his 69 yards in the first half against a Chargers defense that had held its previous six opponents to an average of 86 yards on the ground.  “We weren’t a pushover,” White said. “They had to fight for it.”  From the second quarter on, Rivers repeatedly heaved the ball into the pewter sky. He connected with Chambers on a 30-yard play on one possession, but the drive stalled at the Titans’ 41.  On the first play of the Chargers’ next possession, Rivers threw 42 yards toward Chambers in the end zone, but the pass was intercepted by Cortland Finnegan. On San Diego’s next possession, Rivers connected with Jackson on a 32-yard pass up the middle on third-and-12 to set up a 45-yard field-goal attempt by Nate Kaeding, who missed it. It appeared the Chargers were on their way to another jarring January.  In the locker room at halftime, Rivers said, the Chargers looked at the bright side: as badly as their offense had played, they were one touchdown from taking the lead.  After driving 86 yards on their opening possession, the Chargers settled for a 20-yard field goal from Kaeding. Then came consecutive touchdown drives, covering 78 and 72 yards.  Rivers, who finished 19 of 30 passing for 292 yards, has been inexorably linked with the Giants’ Eli Manning since the day in 2004 when he was drafted No. 4 over all by the Giants, then shipped to San Diego for Manning, the Chargers’ No. 1 pick. Manning had no interest in playing for a franchise so lost it appeared to need a compass.  In the earlier wild-card game Sunday, Manning, whose inconsistency has earned him many critics, broke through for his first playoff victory, leading the Giants past the Buccaneers.  A few hours later, Rivers would answer his critics, setting off a citywide celebration that felt more like an exorcism.  A sports chart on Monday with a preview of the next round of N.F.L. playoff matchups misstated, in some copies, the records of four teams that advanced from the first round. The Giants and the Seattle Seahawks are 11-6, not 10-6; the Jacksonville Jaguars and the San Diego Chargers are 12-5, not 11-5.  A version of this article appears in print on , on Page D4 of the New York edition with the headline: Chargers Show They Can Win in Postseason. Order Reprints| Today's Paper|Subscribe
Chargers quarterback Philip Rivers orchestrated multiple second-half scoring drives and running back LaDainian Tomlinson scored a key touchdown to lead San Diego.