Coming off their divisional home win over the Panthers, the Falcons flew to Qualcomm Stadium for a Week 13 interconference duel with the San Diego Chargers.  In the first quarter, Atlanta took off as kicker Jason Elam got a 35-yard field goal.  The Chargers responded with RB LaDainian Tomlinson getting a 3-yard TD run, yet the Falcons stayed close with Elam getting a 40-yard field goal.  In the second quarter, Atlanta regained the lead as rookie quarterback Matt Ryan completed an 18-yard TD pass to TE Justin Peelle, along with their defense forcing opposing quarterback Philip Rivers to commit intentional grounding from his own endzone, giving Atlanta a safety. In the third quarter, San Diego answered with safety Eric Weddle returning a fumble 86 yards for a touchdown (with a failed two-point conversion).  In the fourth quarter, the Falcons replied with Ryan completing a 5-yard TD pass to rookie WR Harry Douglas.  The Chargers tried to come back, as kicker Nate Kaeding nailed a 28-yard field goal.  Atlanta's defense stiffened for the victory.. How had the longest touchdown run?