Swansea City suffered more late heartbreak as an own goal by Matt Grimes in stoppage time saw them fall to a fourth defeat in a row against Preston.
Having lost to a last-gasp Birmingham penalty on Friday, the Swans had looked set to end their sequence of defeats - and were pressing for a winner - when a shot from a half-cleared corner fell to Scott Sinclair in the 91st minute.
Freddie Woodman got down to make the save, but the deflection off the keeper hit the covering Grimes and bounced into the back of the Swansea net.
After a quiet first half the hosts had been improved after the break, with Morgan Whittaker and Jamal Lowe having shots blocked, while Ben Cabango had headed a good chance wide in the first half.
However, Preston had created a handful of good chances, with midfielder Brad Potts spurning three of them.
The Swans showed four changes from defeat at Birmingham as Cabango, Ryan Manning, Hourihane and Whittaker came into the side at the expense of Ryan Bennett, Jake Bidwell, Korey Smith and Kyle Naughton.
Those alterations also saw a switch of system as the Swans switched to a 4-3-3 formation, and they had a couple of bright early moments through Whittaker.
However, Preston – under the guidance of interim boss Frankie McAvoy – also had reasons to feel enthused as a clever corner saw Ryan Ledson picked out unmarked on the edge of the area, but he saw both his shots blocked by white shirts.
Freddie Woodman held a looping Jordan Storey head in the 16th minute as the visitors looked to threaten on the counter, before Potts fired over after the Swans had got themselves in bother playing back from a free-kick on halfway.
Jamal Lowe led Swansea’s best attack just past the half hour and found Whittaker, who cut infield and got away a left-footed shot that was blocked by Liam Lindsay.
But Preston went straight up the other end and Woodman made a superb fingertip stop from the lively Potts.
Cabango rose to meet a superb Hourihane delivery, but the Wales international could only direct his header wide of the target.
It remained goalless at the break, but Swansea did start the second half with greater zip in their play.
Whittaker again saw a shot blocked, this time following a tee-up from Lowe after Connor Roberts had spotted Manning from in space on the opposite flank.
Jay Fulton drove over from around 25 yards, while Lowe snatched at an effort after being found by Manning.
The Swansea forward was then booked after going down as he raced to beat keeper Daniel Iversen to a Roberts pass.
At the other end, Matt Grimes made a crucial challenge after Potts had been sent scampering towards the Swansea goal, with the captain’s touch ensuring the midfielder’s shot was deflected over the bar.
Whittaker continued to threaten down the Swansea right, but he could not find a fellow white shirt after twice getting to the byline to clip in a pair of right-foot crosses.
Swansea were pressing for a winner but could not find the final ball to break down a stubborn Preston defence and it needed an outstanding late block from Cabango to prevent Jayson Molumby finding the net at the other end.
But, from the resulting corner, the visitors snatched victory with the help of a slice of fortune.
Swansea City: Freddie Woodman; Connor Roberts, Ben Cabango, Marc Guehi, Ryan Manning; Jay Fulton, Matt Grimes (captain), Conor Hourihane (Yan Dhanda 80); Jamal Lowe, Andre Ayew, Morgan Whittaker (Wayne Routledge 81).
Unused Substitutes: Ben Hamer, Ryan Bennett, Korey Smith, Joel Latibeaudiere, Jake Bidwell, Kyle Naughton, Ollie Cooper.
Preston: Daniel Iversen, Sepp van der Berg, Liam Lindsay, Jordan Storey, Andrew Hughes, Ben Whiteman, Ryan Ledson (captain), Emil Riis (Scott Sinclair 75), Ched Evans, Tom Barkhuizen, Brad Potts (Jayson Molumby 80).
Unused Substitutes: Mathew Hudson, Tom Bayliss, Louis Moult, Paul Gallagher, Jayson Molumby, Paul Huntington, Lewis Coulton, Billy Bodin.
Referee: Peter Bankes