From Fryatt's kick-off the ball went to Johannes Gudjonsson and then from Stephen Hughes to Gareth Williams who slipped the ball forward to Fryatt who had the time and space to guide home an angled shot beyond the advancing Carlo Nash from 10 yards.
Gudjonsson then tested Nash but this time the keeper was alert to the danger diving smartly to his right to block the Icelander's 25-yard drive.
Alan Maybury kept the Foxes' noses in front on 17 minutes when he headed a Simon Whaley effort off the line.
Paul Henderson then sprinted from his line to dive bravely at the feet of Jason Jarrett as Preston battled to claw back their early reverse.
But after Gudjonsson had again tried his luck with a trademark thunderbolt, Fryatt almost doubled the lead when his run almost saw him round Graham Alexander only to be denied by a acrobatic on-handed save from Nash.
However, the Lilywhites continued to press and levelled just seconds from the break when Whaley beat Patrick Kisnorbo before driving a 20-yard shot beyond Henderson.
And four minutes after the restart North End found themselves in front when Claude Davis nodded on a Chris Sedgwick corner for Jarrett to head home from close range.
Despite plenty of possession City struggled to find a way beyond Preston's well-drilled defence and with 13 minutes remaining Leicester boss Rob Kelly sought to boost his firepower in a gamble which saw midfielder Maybury sacrificed for a third striker in Chris O'Grady.
And with five minutes remaining Leicester finally rattled Preston when a Gudjonsson free-kick was only half cleared and the ball fell to Iain Hume whose eight-yard shot was brilliantly beaten away by the keeper.