Hoping to get their first win of the season, the 49ers went home for a Week 5 Sunday night duel with the Philadelphia Eagles.  The Niners delivered the game's opening strike in the first quarter as quarterback Alex Smith hooked up with wide receiver Michael Crabtree on a 7-yard touchdown pass, but the Eagles would answer with quarterback Kevin Kolb completing an 8-yard touchdown pass to tight end Brent Celek.  Philadelphia took the lead in the second quarter as kicker David Akers made a 33-yard field goal, followed by running back LeSean McCoy's 29-yard touchdown run.  Afterwards, San Francisco closed out the half with kicker Joe Nedney booting a 50-yard field goal.  After a scoreless third quarter, the Eagles would add onto their lead in the fourth quarter as safety Quintin Mikell returned a fumble 52 yards for a touchdown.  The Niners began to rally as Smith found tight end Vernon Davis on a 7-yard touchdown pass, yet Philadelphia answered with a 45-yard field goal from Akers.  San Francisco tried to rally as Smith found running back Frank Gore on a 1-yard touchdown pass, but Philadelphia's defense would hold on for the win. With the loss, the 49ers fell to their first 0-5 start since 1979.. Who threw the first scoring pass?