Swindon came from behind to thrash in-form League One side Huddersfield.
The visitors went ahead when Lee Novak found the bottom left corner with a shot from the edge of the area.
Aden Flint headed the Robins level before Simon Ferry slid the ball across the six-yard box for Raffaele De Vita to put the League Two side ahead.
Substitute Mehdi Kerrouche slotted in Etienne Esajas's cross for 3-1 before Ferry fired in a late fourth to seal Swindon's place in the second round.
VIEWS FROM THE DRESSING ROOM
Swindon manager Paolo di Canio told BBC Wiltshire:
"What we did today was amazing. We went 1-0 down then came out of this situation and scored four goals. We deserved to win 4-1.
"That shows what a group of professionals I have, how they work so hard during the training session.
"If we keep going in this way with passion, desire, as a manager I can relax for two minutes."
Huddersfield Town manager Lee Clark told BBC Radio Leeds:
"I'm really disappointed. In cup ties there's a chance you can lose but it's how you lose.
"We only worked their goalkeeper once in the second half. But we didn't cross any balls and didn't have enough shots so we've gone out with a bit of a wimper.
"They all had a part to play (in the defeat) but we have to get them up and running again."