Marvin Ekpiteta’s fine touch and turn led to the Tangerines defender cancelling out Marcus Tavernier’s eighth-minute opener just after the hour.
And Middlesbrough defender Grant Hall was left with his head in his hands after he turned a corner into his own net in the 78th minute to hand Blackpool a second win since returning to the second tier of English football.
Ekpiteta and Tavernier’s goals drew complaints from the opposition and in the end it was Hall’s own goal that proved decisive in giving Neil Critchley’s side all three points.
It looked like Middlesbrough were set for back-to-back wins after the midweek success at Nottingham Forest.
On loan Norwich player Onel Hernandez and Tavernier’s quickly-taken corner resulted in James Lea Siliki, on loan from Rennes, clipping a ball to the back post.
Dael Fry was allowed the space to knock a pass back across the six-yard box, where Tavernier had coasted in undetected to convert from close range. The calls for offside centred on a flick-on from Lee Peltier before it arrived at Fry’s feet.
Blackpool should have levelled six minutes later when Ryan Wintle’s cross found Tyreece John-Jules unattended at the back post. He looked certain to score but fired over after turning inside Fry.
Otherwise it was Middlesbrough who threatened the most in the opening half an hour, even though Blackpool goalkeeper Chris Maxwell did not have too much to do.
Andraz Sporar, on loan from Sporting Lisbon, came closest to adding to the lead during that period when his first time effort from Tavernier’s pass hit the woodwork.
After the restart Blackpool sensed they could get back into the contest.
With the hour approaching Shayne Lavery poked his foot out to direct an effort towards goal after Middlesbrough goalkeeper Joe Lumley made a mess of a cross into the box. The effort shaved the post and went wide.
Not long after, with Boro boss Neil Warnock and his players fuming about a couple of decisions from referee David Webb, the experienced Richard Keogh received a quick free-kick.
His delivery to defensive partner Ekpiteta was brought down on his thigh and the defender turned Fry before beating Lumley brilliantly. The goal set up an exciting finish.
Sporar went close first for the home side when he darted beyond his man before seeing a low effort well saved by Maxwell.
But it was Blackpool who got the decisive third goal of the game with 12 minutes remaining when Hall knew very little about Luke Garbutt’s corner hitting him and finding his own net.
After that, Boro tried to push in search of avoiding defeat. Substitute Martin Payero curled 25-yard drive against the crossbar before his free-kick was then saved by Maxwell.
However, Blackpool – impressive throughout the second half – continued to threaten and it was the travelling support who were left celebrating at the end of six additional minutes of time.