Preston captain Paul McKenna hit a 25-yard right-foot shot narrowly wide after 13 minutes.
Gary Taylor-Fletcher shot wide of the keeper's left-hand post from a Hoolahan cross after 16 minutes.
Michael Flynn had a shot saved and then Ben Burgess had a header saved by Preston keeper Andy Lonergan.
In the 33rd minute, Paul Gallagher found Patrick Agyemang and he rounded the goalkeeper but the angle was so narrow that his weak shot was cleared off the line by Kaspars Gorkss.
Just before half-time, Chris Sedgwick brought a save out of Blackpool keeper Paul Rachubka.
Sean St. Ledger had a shot deflected over the bar for a right-wing corner and Shaun Barker had a header saved early into the second half.
Preston old boy and now Blackpool captain Michael Jackson was substituted by Ian Evatt after 65 minutes.
The turning point of the game came after 68 minutes when Youl Mawene made a poor challenge on Burgess in the penalty area and the referee pointed to the penalty spot.
Hoolahan, Blackpool's man of the match, chipped a left-foot penalty over Lonergan into the centre of the net for the game's decisive moment.
Chris Sedgwick was booked for a foul on Stephen Crainey and substituted straight away by Lewis Neal.
Preston had lost their shape and substitute Jones was booked for a foul on Hoolahan.
Paul McKenna was also booked for a foul on Hoolahan, before substitute Ian Evatt was booked for a foul and Paul McKenna hit a free-kick against the bar right at the end.