The Terriers looked set to end a winless run of seven games thanks to Anthony Gerrard's first goal for the club shortly after the hour-mark.
But just as the points seemed safe, Seasiders substitute Nathan Delfouneso converted Tom Ince's cross to snatch the hosts a share of the spoils and deny Grayson's men a morale-boosting victory.
"I certainly would have taken a point after the first 45 minutes," he said afterwards.
"We never got out of the traps and Blackpool could have been out of sight by half-time.
"When you get 1-0 up into injury time you think 'we'll take the result, not the performance', and if we'd got three points it would have only papered over the cracks of how poor we were in the first half.
"To get a point out of that first-half performance is the only positive really."
Huddersfield, who currently sit in 15th place in the Championship, are in action again on Saturday when they host struggling Sheffield Wednesday.