Costly breakdowns helped send the Eagles to a 32-25 loss to the Arizona Cardinals on Sunday afternoon, Philadelphia's fourth defeat in five conference title games since 2002.
A unit that limited the Minnesota Vikings and New York Giants to a total of 25 points in two postseason victories gave up 24 in the first half.
The defense showed flashes of its old form in the second half, but couldn't close out the game when it had to.
Behind Donovan McNabb's three touchdown passes, the Eagles rallied for a 25-24 lead early in the fourth quarter. But the once-reliable defense couldn't make it stand up.
The Eagles let the Cardinals march 72 yards on 14 plays, including an 8-yard touchdown pass from Kurt Warner to Tim Hightower with 2:53 to go.
It was one of four touchdown passes for Warner, who got little pressure from a defense that ranked among the NFL's sack leaders. The Eagles also failed to intercept any of Warner's 28 passes.
The most glaring defensive blunder came in the second quarter, when free safety Quintin Demps fell down on a 62-yard flea-flicker, allowing Cardinals star Larry Fitzgerald to catch an underthrown ball and waltz into the end zone.
It was one of a record-tying three touchdown catches for Fitzgerald, whom the Eagles simply couldn't cover.