After a fairly eventless opening, Coventry took the lead with a well-worked goal in the 21st minute.
Gary McSheffrey collected the ball on the left-hand side of the penalty area and instead of blasting into a sea of bodies, he pulled the ball back for James Bailey who side-footed past Preston goalkeeper Thorsten Stuckmann for his first goal of the season.
Preston had a golden chance to draw level on the half-hour mark when the impressive Holmes crossed from the left.
Andy Proctor looked destined to head home from inside the area, but it somehow came off his shoulder and Coventry cleared the danger.
The home team had a couple of long-range shots in a bid to extend their lead, but Preston almost went in level when David Amoo broke clear, only to hit the crossbar.
The visitors deservedly drew level in the 77th minute when Holmes broke clear and tucked the ball into the bottom corner past on-rushing Coventry goalkeeper Joe Murphy.