Two sublime examples of finishing from Woking's top marksman, Justin Richards, sandwiched goals from Grays strikers Jamie Slabber and Aaron McLean in a pulsating game.
The Cards opened the scoring in the 17th minute when a huge kick from keeper Shwan Jalal was flicked on by Craig McAllister to Richards who broke clear of the home defence and lobbed Nicky Eyre with aplomb.
Grays responded immediately and three minutes later they were level. Stuart Thurgood's corner was only half-cleared by Jalal, and when John Martin's follow-up was blocked by the England National Game keeper, Slabber was on hand to stab home from close range.
Two minutes later and Grays were in front. Tom Hutchinson failed to cope with Slabber after a deep Cameron Mawer cross had picked the in-form striker out, and the ball fell kindly for McLean who stroked the ball past Jalal from six yards.
Had it not been for a fabulous finger-tip save from Eyre it would have been 2-2 a minute later after Richards beat everyone to Gary MacDonald's long throw and struck a crisp volley that was heading into the bottom corner until Eyre's intervention.
Eyre was tested again minutes later when Karl Murray stuck a fantastic effort from 35 yards that the ex-Spurs youngster tipped over.
At the other end, Thurgood missed a glorious opportunity after a rapier-like attack caught the visitors cold but the Grays skipper's finish flashed agonisingly wide of the post and Jamie Stuart volleyed just wide after finishing room in the box.
McAllister hacked off the line from Michael Kightly's deft touch from a Glenn Poole corner in the second period and in a neat twist McAllister watched as his own shot was scrambled from the Grays line by Christian Hanson.
Woking equalised six minutes from time when Murray robbed Martin and played in Richards who strode away from Stuart and poked the ball into the far corner via the far post.
There was still time for Grays to have a glorious chance to win it when Poole's wonderful cross-field pass found Kightly but the ex-Southend man's touch let him down as Jalal came out and Stuart Nethercott scrambled clear.