Peterborough United slipped to a second successive defeat to teams in the play-off positions, but will feel heartened by their display at Deepdale and created numerous good opportunities in front of goal only to be let down by good goalkeeping or poor finishing.
Paul Gallagher had the first effort of the game for the hosts, but his skidding effort went wide of Olejnik's right hand post.
Declan Rudd made a routine stop from a speculative effort from Danny Swanson on six minutes. Gallagher clipped the top of the crossbar with a superb curling effort on 17 minutes after cutting inside Baldwin on the left hand side.
Posh broke the deadlock on 18 minutes and it was an excellent strike from Danny SWANSON who fired home from the edge of the box past Rudd. Swanson found out he was to be a father this week, he celebrated that news in style.
Bailey Wright fired over from a corner kick on 20 minutes as Preston responded well to the setback of falling behind. Kilkenny saw a shot deflected wide for a corner kick as the game reached the 30 minute mark.
Assombalonga was denied by Rudd moments later, Ajose picking the striker out, but his low left-foot drive was well saved by the legs of Rudd.
On 44 minutes, the home side drew level as Gallagher fed KILKENNY who drove low across Olejnik and into the bottom corner of the net. In stoppage time, Baldwin was cautioned for a tackle from behind on Garner in stoppage time.
Posh went close to scoring on 57 minutes as Newell fed Ajose, the striker's shot was deflected over the bar from close-range. From the resulting corner kick, Alcock powered a header towards goal, but a combination of Rudd and a defender on the line kept the effort out.
Posh were screaming for a penalty for a possible handball against Wright as Ajose raced clear, but nothing was given by the official.
On 78 minutes, Preston nudged themselves in front as Gallagher worked a bit of space thanks to a bit of good fortune, his shot struck the post and rebounded kindly for GARNER who couldn't miss from three yards.
Moments after conceding, a free-kick from Swanson caused panic with Preston struggling to clear before the referee spotted a foul and gave the hosts a free-kick. Nugent was then cautioned for dissent.
In stoppage time, Posh leaked a third goal as GARNER fired home from 10-yards after Gallagher held off the attentions of Little with Posh pushing everyone up front to try and find an equaliser.
Final Score: Preston North End 3-1 Posh
Preston: Rudd, Wright, Humphrey (sub Holmes 63min), Beavon, Gallagher, Garner, Buchanan, Welsh, King, Wiseman (sub Keane 25min), Kilkenny (sub Browne 77min). Unused subs: Stuckmann, Laird, K. Davies, C. Davies.
Posh: Olejnik, Little, Alcock, Baldwin (sub McQuoid 46min), Nugent, Bostwick, Swanson, Payne, Newell, Ajose (sub Washington 72min), Assombalonga. Unused subs: Day, Brisley, Knight-Percival, McCann, Isgrove.