Stoke 3-4 Swindon (aet)
James Collins scored an extra-time winner for Swindon to send Stoke crashing out of the League Cup.
Swindon took the lead when home keeper Thomas Sorensen dropped a cross and Collins pounced, before the same player added a second with a header.
A Kenwyne Jones header and Jon Walters shot hauled Stoke level but Aden Flint gave Swindon the edge in extra-time.
Peter Crouch nodded in another Stoke equaliser before Collins completed his hat-trick when he slid in to score.
It was a pulsating game at the Britannia Stadium and the League One side needed to show plenty of character to see off their Premier League hosts.
The visitors were given a helping hand when Sorensen, one of six Stoke changes from Sunday's draw with Arsenal, spilled a James McEveley cross to allow Collins to net his first.
Raffaele De Vita crossed for Collins to head home and extend the Robins' lead, and the former Shrewsbury striker was then denied a third when he had a shot cleared off the line.
De Vita also saw an effort hit the post before the home side went into half-time and regrouped.
Revived, the Potters pulled one back when Jones headed home a Michael Kightly cross and substitute Walters then stroked home after 86 minutes to send the tie into extra-time.
The home side appeared to be getting on top but it was Swindon who regained the lead.
Joe Devera flicked on from a corner and defender Flint was at the back post to head in.
Crouch again levelled for Stoke only for Collins to get his third, and the winner, with penalties just a minute away.
Stoke boss Tony Pulis: "I don't want to take anything away from them - I think they should celebrate the fact that they have come here and won.
"We have had a few years of being successful in cup competitions, some really good days in the cup, and they have had a good day today so let them celebrate.
"They played a major part in what was an extraordinary game at times tonight."
Swindon boss Paolo Di Canio: "It is obvious that when you win against a side like Stoke City away from home - in a place where teams like Arsenal and Manchester United find it difficult to score even one goal and you are playing in a fortress - it is something special.
"We scored four goals and I don't want to exaggerate, but I think we created another five or six clear chances to score.
"I don't think they underestimated us and all the congratulations I received from [Stoke manager] Tony Pulis at the end of the game was special for me because he is an experienced and very good manager who has achieved fantastic things with Stoke.