For the first time in their 40-year history, the Saints will play for the conference championship. They will face the winner of Sunday's Seattle-Chicago contest.
The Eagles took an eight-point lead early in the second half on the second of Brian Westbrook's two touchdown runs -- a 62-yarder.
New Orleans then drove 63 yards and McAllister scored from five yards out to get the Saints within one. Quarterback Drew Brees next drove the Saints 84 yards in nine plays with McAllister scoring on an 11-yard run.
New Orleans had a goal-line stand in the fourth quarter to limit the Eagles to a field goal and then survived a late fumble by running back Reggie Bush that gave Philadelphia the ball at midfield.
The Eagles appeared to convert a fourth-and-10 situation in the final two minutes, but the play was called back on a motion penalty. They then punted and the Saints were able to run out the clock.