Referee James Tatten adjudged Grand's 88th minute header to be over the line after it had cannoned down off the crossbar.
Despite a massive protest from Woking and boss Glenn Cockerill, the Merseyside official refused to reverse his decision.
Just four minutes earlier Blues midfielder Chris Lumsdon had pulled his team level when he curled in a spectacular goal direct from a corner.
Until the equaliser Woking had frustrated Carlisle with a performance that owed more to brute strength and niggling fouls than silky footwork.
But this method paid dividends for Cockerill's men when they scored their own hotly-disputed goal.
Within 60 seconds of the second half starting, Jefferson Louis found space on the left wing, but his cross appeared to be handled by Justin Richards before the big striker turned to pick his spot and finish well.
A dismal first half saw Carlisle's top scorer Karl Hawley miss when clean through and Woking's Scott Canham send a fizzing drive narrowly over.