The 35-year-old midfielder, on loan from Birmingham, capped an excellent contribution when his low shot from the corner of the box took a deflection to beat Preston goalkeeper Declan Rudd.
The visitors had gone ahead six minutes earlier, also with the aid of a deflection, as defender Jake King lashed home from 12 yards after City had failed to clear a free-kick.
Rudd had made a flying save to deny City's Karleigh Osborne following a 57th-minute corner and substitute Tyrone Barnett wasted a great chance to win it for the hosts four minutes from time when firing over from 10 yards.
The best chances of an even first half fell to Preston's Joe Garner, who had one header well saved by Coventry goalkeeper Frank Fielding, another narrowly wide and also shot over from 15 yards when well placed to score.
Sam Baldock shot just wide from a narrow angle for City, while Martin Paterson's cross from the right fizzed across goal without anyone applying the final touch.