Coming off their bye week, the Falcons flew to Candlestick Park for a Week 5 duel with the San Francisco 49ers.  Atlanta took off in the first quarter with running back Michael Turner's 7-yard touchdown run, followed by quarterback Matt Ryan hooking up with wide receiver Roddy White on a 31-yard touchdown pass.  The 49ers would answer with running back Glen Coffee getting a 2-yard touchdown run.  San Francisco would start off the second quarter with kicker Joe Nedney making a 39-yard field goal, but the Falcons would begin to soar.  It started with Ryan's 90-yard touchdown pass to White and concluded with Turner's 3-yard and 1-yard touchdown runs.  Atlanta would then close out the game with kicker Jason Elam's 40-yard field goal in the third quarter and Ryan's 1-yard touchdown run in the fourth. Atlanta's 35 first-half points would become the best opening half performance in franchise history.. How many yards was the longest touchdown run?