INDIANAPOLIS — As the final seconds ticked down, tailback LaDainian Tomlinson, the face of the San Diego Chargers, bounced from teammate to teammate in celebration of one of the biggest victories in franchise history.

He was thanking them for doing the work he was unable to.

Tomlinson didn't have a big hand in his team's 28-24 AFC semifinal upset yesterday of the reigning world champion Indianapolis Colts, having left the game in the first half with a knee injury. And while Philip Rivers threw for 264 yards and three touchdowns, the starting quarterback of the Chargers wasn't the engineer of record when the offense drove to the go-ahead score in the fourth quarter. Rivers went out with a knee injury, too.

"Guys stepped up and got it done," Tomlinson said.

Their names were Billy Volek, Michael Turner, Darren Sproles and Legedu Naanee.

Who?

Exactly.

Without them, the Chargers (13-5) would not be headed next weekend to Foxborough, Mass., where they'll be huge underdogs against the New England Patriots (17-0) in the AFC Championship Game at Gillette Stadium.

"I've never been around a more gutsy performance by a team," said San Diego coach Norv Turner, putting particular emphasis on that last word. "The things that happened over the course of the game — the injuries and all those things — our guys never backed down. It's one I'll remember."

And one the Colts (13-4) will just as soon forget.

Peyton Manning threw for 402 yards and three touchdowns, but the Indy offense broke down with three turnovers deep in San Diego territory (including two inside the 5) and twice surrendered the ball on downs in the final 2:01 (the first time at the Chargers' 7).

"We did a good job of getting down there (in scoring position)," Manning said. "Just couldn't quite finish it."

They couldn't do what Volek — with just 10 starts in his eight pro seasons — and his band of fellow backups were able to do when it mattered most. They did it in the face of adversity, too. San Diego was hit with 10 penalties, one of which was a questionable holding call that nullified a 93-yard interception return for a touchdown at the end of the first half.

The Chargers maintained their poise.

"I had to go out and do my role," said Volek, who completed 3 of 4 passes for 43 yards and ran for a touchdown. Rivers was hurt when throwing a 56-yard TD screen pass to Sproles that gave the Chargers a 21-17 lead.

With Indy up 24-21, Volek's comeback was aided by a pass-interference call against Marlin Jackson and a quick screen to Naanee for 27 yards that helped set up Volek's 1-yard scoring sneak with 4:54 remaining for a 28-24 lead.

It came down to defense. Shawne Merriman forced a poor throw by Manning on fourth-and-goal from the Chargers' 7 just before the two-minute warning. And after a punt, it was a hard rush by linebacker Shaun Phillips doing the same on fourth-and-5 from the Colts' 37.