Coming off their overtime road win over the Titans, the Chargers went home for a Week 15 interconference duel with the Detroit Lions.  In the first quarter, the 'Bolts struck first with RB LaDainian Tomlinson getting a 6-yard TD run, Kicker Nate Kaeding getting a 22-yard field goal, and Tomlinson getting a 2-yard TD run.  In the second quarter, San Diego continued its domination with Kaeding getting a 22-yard field goal and LB Shaun Phillips returning an interception 18 yards for a touchdown.  The Lions would get on the board with QB Jon Kitna completing a 9-yard TD pass to WR Brandon Middleton.  The Chargers would end the half with QB Philip Rivers completing a 1-yard TD run to TE Brandon Manumaleuna. In the third quarter, San Diego continued its annihilation with RB Darren Sproles getting a 1-yard TD run and Kaeding nailing a 45-yard field goal.  Detroit would get its final points of the game as Kitna completed a 17-yard TD pass to WR Shaun McDonald.  In the fourth quarter, the Chargers ended its day with Sproles getting an 11-yard TD run. With the win, not only did the Chargers improve to 9-5, but they also clinched their second-straight AFC West title. For Darren Sproles (25 attempts for 122 yards and 2 touchdowns) and LaDainian Tomlinson (15 attempts for 116 yards and 2 touchdowns), they became the first RB duo in franchise history to both get 100 rushing yards in the same game.  Also, Tomlinson ended this part of his career with 127 career touchdowns, surpassing Jim Brown for 7th All-Time.. How many touchdowns did Tomlinson score during the first quarter?