Preston's winning run came to an end at the Madejski Stadium as Reading twice came from behind to snatch victory.
John Mackie and Nicky Forster struck in the final eight minutes, capping a spell of concerted second-half pressure and denying Preston what would have been a fourth successive victory.
Shaun Goater, with a contentious re-taken penalty, had equalised Ricardo Fuller's opener for the visitors, who saw Graham Alexander's spot-kick cancelled out by Mackie.
Forster's header four minutes into stoppage-time secured a second successive victory since Steve Coppell took over as manager from Alan Pardew.
Although Preston will feel somewhat aggrieved at Goater's goal, they deserve credit for a spirited performance following Marlon Broomes' first-half sending-off.
Fuller twice fired wide in the first quarter-of-an-hour, although it needed a well-timed block from Broomes to deny Goater from six yards before Preston broke the deadlock.
Fuller collected Michael Keane's well-weighted through-ball to beat Hahnemann with a low drive in the 20th minute, his eighth goal of the season.
If Fuller was fortunate to see his shot find its way into the net via Marcus Hahnemann's body, Reading's leveller owed much to a spot of contentious refereeing.
Goater's penalty - awarded for Broomes' foul on Nicky Forster - hit a post, but he was given a chance to redeem himself after Preston goalkeeper David Lucas was deemed to have moved off his line before the kick was taken.
Preston's misery at having Broomes dismissed for a second bookable offence was compounded by Goater, who found the bottom corner of Lucas' goal with his second attempt.
Scott Murray responded for Reading with a wayward strike from 18 yards, while Nicky Shorey crossed for Goater to head against the woodwork.
The former Manchester City striker was not to be denied for long, however, making the most of his second opportunity from the spot six minutes before the interval.
Graham Alexander copied Goater's feat upon the restart, although he needed just one opportunity to beat Hahnemann after Steve Sidwell was penalised for a foul on Richard Cresswell.
Gould's fumbling of a Murray shot reflected Preston's nerves as Reading began to crank up the pressure, and Murray hit the woodwork from six yards.
The pressure told in the 82nd minute, John Salako crossing for Mackie to head home at the far post.
Salako was again the provider for the winning goal, the former England international this time sending over a centre from the right which Forster met to devastating effect.
Reading: Hahnemann, Newman, Shorey, Mackie, Williams, Murray,
Sidwell, Harper, Hughes, Goater, Forster. Subs: Ashdown, Watson,
Salako, Savage, Tyson.
Preston: Gould, Alexander, Broomes, Jackson, Lucketti, McKenna,
O'Neil, Keane, Lewis, Fuller, Cresswell. Subs: Lonergan, Healy,
Edwards, Etuhu, Davis.
Referee: A Hall (West Midlands)