Their response was impressive with Ross Wallace hitting the outside of the post and Jon Parkin firing just over before they got their equaliser 12 minutes later.
It was something of a gift from home right-back Bradley Orr, who gave away a needless corner and Preston centre-back Youl Mawene was able to stretch in front of a defender to knock the ball past Brazilian keeper Adriano Basso.
It was a game high on corners - 20 in all - and this was Preston's ninth.
Maynard's headed goal, skilfully steered well wide of the keeper, was set-up by Dele Adebola, who had gone out to the left touchline to win possession.
Little had been going right for either of the City forwards and Adebola, linked with a summer move to Sheffield Wednesday, had passed up two chances in an earnest first-half lacking in subtlety.
Preston found it difficult early on to handle City's eager pace but both sides seemed content later to cancel each other out.
Wallace was behind many of Preston's best attempts on goal and once found a big gap in City's midfield to fire a 25-yard shot which Basso managed to control at the second attempt.
The visitors best chance before their equaliser came late in the opening half when Stephen Elliott outwitted Liam Fontaine near the byline. A short cross looked certain to bring a goal but Parkin completely missed his kick.
As if in sympathy, Maynard, minutes later, rolled a shot the wrong side of the left-hand post after Preston had been opened up by a three-man raid down the right.