Palace seemed to be cruising as England hopeful Andy Johnson struck twice with goals on 28 and 45 minutes.
But Crewe, facing a desperate battle to avoid the drop, made a spirited fight back as Luke Rodgers on 68 minutes and Kenny Lunt from the spot on 79 minutes earned them a point.
While Dougie Freedman had his mis-hit boots on - he wasted two absolute hitters in the first 30 minutes - Johnson thankfully was hitting the ball sweetly.
Tom Soares out on the right touchline accepted a long cross from Marco Reich and immediately placed the ball into the goalmouth for Johnson to drill home from six yards out.
Then right on half-time, Freedman provided a delightful dummy giving Johnson a clear run on goal. The Palace hitman kept his cool by rounding keeper Ross Turnbull before planting the ball into the empty net.
Palace were more than comfortable as Freedman missed yet another glorious chance and Soares saw his shot deflected on to the post.
Crewe somehow survived relentless pressure from the home side before Rodgers, completely against the run of play, gave them a lifeline.
Palace were caught square and the former Shrewsbury man made no mistake with a low 15-yard shot which Gabor Kiraly outstretched left-hand and into the corner.
That was on 68 minutes and 11 minutes later Crewe were level.
Soares was the victim of an awkward bounce and handled with referee Mr Russell not too far away.
The Crewe skipper kept his nerve and struck his kick low past Kiraly and into the left corner for a point that they didn't really deserve.