Ian Holloway's Seasiders have made a habit of producing late strikes in a run of one defeat in 10 that has catapulted them into the promotion picture, by they were given a taste of their own medicine when Fryatt reacted quickest to James Chester's knockdown inside a crowded penalty area.
The hosts deservedly led at the interval after a fine strike from Tom Ince denied Hull a club-record seventh consecutive clean sheet.
Yesterday Blackpool announced they are in talks with ex-England striker Robbie Fowler over a surprise return to English football, but they appeared perfectly well stocked in attack as a four-strong forward line troubled Hull all evening.
Aaron Mclean had a first-half attempt cleared off the line for the visitors, but they had little to show for their efforts until a successful late rally.
Nick Barmby's men close to within a point of the top six and remain four points behind Blackpool in fourth.
Veteran forward Brett Ormerod was rewarded for a lively cameo from the bench in Saturday's win over Bristol City with his first Blackpool start since October - one of three changes made by Ian Holloway.
Seyi Olofinjana and Mclean returned for Hull, with Corry Evans dropping to the bench and Robbie Brady missing out on the matchday 16.
Blackpool almost took an early lead when a speculative effort by midfielder Keith Southern forced backpedalling City goalkeeper Vito Mannone to push over his crossbar in the fifth minute.
Mannone was at full-stretch once more from the resulting corner as Alex Baptiste rose to meet Ince's well-flighted delivery.
The home side's expansive and enterprising front four kept them in the ascendancy, with Ince the shinning light. In the ninth minute he left Tigers full-back Andy Dawson in his wake and Mannone was alert to punch clear as the ball fizzed towards his goalmouth.
Inevitably there was space to exploit on the break, but Hull rarely did so in the opening period. When Seasiders goalkeeper Matt Gilks recklessly strayed from his area in the 19th minute, Baptiste was on the line to head Mclean's curling effort to safety.
Hull's goal had not been breached for 610 minutes when a superlative strike brought their run to an end.
Ince collected the ball 25 yards from goal and played a delicate one-two with Kevin Phillips before rifling past Mannone with the outside of his left foot.
Phillips nodded wide from Ormerod's hooked cross as the Seasiders' first-half showing failed to produce the second goal it merited.
Hull hustled their way onto the front foot at the start of the second period, but at the expense of their typical solidity as Roman Bednar and Phillips found space to draw fine saves from Mannone in quick succession.
Ince continued to be a menace with the ball at his feet but should have done better when he headed Neal Eardley's cross wide at the far post in the 66th minute.
Hull introduced on-loan Manchester United striker Joshua King as they attempted to force a point and, after picking out Gilks with a free header, he stung the Blackpool keeper's palms with a fierce 83rd-minute drive.
It appear a case of too little, too late until Fryatt's poacher's instincts stole a share of the spoils.