Match ends, Coventry City 1, Cardiff City 2.
Championship side Cardiff knocked League One Coventry out of the Capital One Cup at Northampton's Sixfields Stadium.
Guido Burgstaller's low finish gave the Bluebirds an early lead.
Cardiff looked to have sealed victory when Coventry defender Ryan Haynes turned Mats Moller Daehli's cross into his own net.
But Sky Blues striker Shaun Miller converted a Haynes cross to ensure a nervy ending for the Welsh club.
Ole Gunnar Solskjaer's side dominated early on and pressed high up the pitch when they were without the ball, making it difficult for Steven Pressley's side to break out of their own half.
Magnus Wolff Eikrem's long pass over the top of the Coventry defence found Nicky Maynard, who played the ball into the path of Burgstaller to shoot low into the corner to put Cardiff ahead.
Solskjaer's side struggled to make their dominance count and Coventry came back into it towards the end of the match.
They should have drawn level 13 minutes from time when Miller blasted the ball over the bar with just Cardiff goalkeeper Simon Moore to beat.
Three minutes from time it looked as if Cardiff's passage to the second round was safe, when full-back Haynes hit the ball high into his own goal, under pressure from Cardiff's Kadeem Harris.
But 90 seconds later Haynes made amends crossing the ball for Miller to fire past Moore.
Cardiff now face League One Port Vale in the second round.
Coventry manager Steven Pressley told BBC Coventry and Warwickshire:
"We were a little bit nervous in the early part of the game, and we didn't quite get the balance right between staying and pressing, and we got picked off on a few occasions, but I thought we grew into the game.
"I thought we were really good in the second half, I thought we got the balance right, and I think we look a danger on the break, I really do.
"We have to win games of football, but when you look over the piece, I think there's a lot to be encouraged about."
(On being linked to the Huddersfield managerial vacancy): "It's obviously flattering to be linked with such a job, but I am truly happy at this football club.
"I really enjoy it, I've started what I believe is a long journey in terms of the development of this club. There's a lot of work to be done over the coming years and I certainly hope I'll be here to see it through."
- 3PughSubstituted forHaynesat 51'minutes
- 17DanielsSubstituted forMillerat 62'minutes
- 9McQuoidSubstituted forMaddisonat 69'minutes
- 55Barnum-BobbSubstituted forK Harrisat 66'minutes
- 15Wolff Eikrem
- 16ConnollyBooked at 20mins
- 30BurgstallerSubstituted forDaehliat 66'minutes
- 13KimSubstituted forO'Sullivanat 84'minutes
- 40K Harris
- Simon Hooper
- Shots on Target
Second Half ends, Coventry City 1, Cardiff City 2.
Attempt missed. Andy Webster (Coventry City) header from the centre of the box is close, but misses to the left.
Corner, Coventry City. Conceded by Matthew Connolly.
Danny Swanson (Coventry City) wins a free kick in the attacking half.
Foul by Tommy O'Sullivan (Cardiff City).
Corner, Cardiff City. Conceded by Jordan Clarke.
Attempt blocked. Joe Ralls (Cardiff City) left footed shot from outside the box is blocked.
Corner, Cardiff City. Conceded by Ryan Haynes.
Attempt saved. Mats Daehli (Cardiff City) right footed shot from the left side of the box is saved in the top centre of the goal.
Foul by Jim O'Brien (Coventry City).
Kadeem Harris (Cardiff City) wins a free kick in the defensive half.
Substitution, Cardiff City. Tommy O'Sullivan replaces Kim Bo-Kyung.
Goal! Coventry City 1, Cardiff City 2. Shaun Miller (Coventry City) right footed shot from the centre of the box to the bottom left corner. Assisted by Ryan Haynes with a cross.
James Maddison (Coventry City) wins a free kick on the left wing.
Foul by Magnus Wolff Eikrem (Cardiff City).
Own Goal by Ryan Haynes, Coventry City. Coventry City 0, Cardiff City 2.
Foul by Shaun Miller (Coventry City).
Magnus Wolff Eikrem (Cardiff City) wins a free kick in the defensive half.
Attempt missed. Shaun Miller (Coventry City) left footed shot from the centre of the box is too high.