The game went into a penalty shoot-out and Barnsley's first four players all scored and when Blackpool skipper Michael Jackson hit a post with his effort and team-mate Keigan Parker had his saved the Tykes were through to the second round.
The game had finished 2-2 after extra time with a remarkable finale carved out in the 116th and 119th minutes.
In the 116th Barnsley sub Martin Devaney stormed past a tired home back four to plant a superb 18-yarder past Rhys Evans.
The 500 travelling fans were delirious after seeing their side survive a virtual siege during the second half of normal time.
But three minutes later Blackpool retaliated and Scott Vernon turned brilliantly in the box to score with a magnificent rising drive. It was a superb strike and needed to be to beat Vito Mannone who had had a superb night in the Barnsley goal.
The game had started calmly enough with Barnsley only managing one corner in the first half from which Blackpool keeper Rhys Evans did superbly to parry away Tommy Wright's point-blank header.
It was in the second half that the tie suddenly sprang into life with both sides playing some excellent football.
In the 50th minute the referee found himself at the centre of attention. The home crowd believed he was far too harsh when he penalised Jackson's challenge on Wright. He awarded a penalty which Wright took and the Seasiders obviously believed some justice was done when Evans saved down to his right.
It was the Barnsley fans' turn to think the night was going their way just three minutes later when the referee awarded them a second penalty when, after the assistance of a linesman, he adjudged that Ian Evatt had handled in the box. Robbie Williams took over the spot-kick duties and beat Evans in the top corner.
Mannone then produced his series of saves which kept Blackpool out until the 70th minute when Vernon headed home David Fox's free-kick.