Substitute Ellis Simms struck a 65th-minute winner as Coventry progressed to the second round of the Carabao Cup with a narrow 1-0 win over Championship rivals Bristol City at Ashton Gate.
The striker had only been on the pitch for a matter of seconds when latching onto Kasey Palmer’s through ball and drilling a low shot past Bristol goalkeeper Stefan Bajic from 12 yards to the delight of nearly 2,500 travelling fans.
The hosts created the majority of first-half chances, Coventry goalkeeper Ben Wilson making a fine double save from Nahki Wells and Sam Bell after 39 minutes and then diving to keep out a shot from Fally Mayulu.
The hosts lost Bell to injury just before half-time, with Harry Cornick replacing him before they had to make another change at the interval, Joe Williams coming on for skipper Jason Knight.
Bajic made two diving saves from Brandon Thomas-Asante – who was making his first Coventry start – early in the second half before boss visiting Mark Robins made five changes after 63 minutes.
One of them saw Simms replace Haji Wright and he wasted no time becoming the ultimate match-winner.
Wilson protected the lead with a diving save from Bristol substitute Anis Mehmeti three minutes from time as the visitors progressed.