Stoke City boss Mark Robins said his side were not at their best but were unlucky to lose out to his former club Coventry City.
Ephron Mason-Clark grabbed a late winner in a tight game of few chances.
"I think the manner of the defeat is even more difficult to take," Robins told BBC Radio Stoke. "I'm disappointed with the result, I'm not disappointed with the effort we showed – the lads have given everything and we've been really competitive.
"I can't remember any clear-cut chances that they had – there was some good play but they play for corners, long throws and put you under pressure that way.