Trebble netted in the 91st minute, giving the Lilywhites their first victory in London for nearly six years.
Since October 1988, PNE had played teams in the capital 14 times.
Fulham had beaten them five times in that run, so this win was long overdue.
It was achieved after they played most of the second half with 10 men.
Striker Mark Sale was sent-off in the 54th minute for two bookings in quick succession.
Having been cautioned for a foul, Sale got a second yellow card and then red for deliberate handball.
Rather than put their 10 men behind the ball to try and hold out for a draw, North End went on the attack.
That policy paid off when substitute Trebble found the net with a fine finish.
North End had headed to London following a 4-0 win over Lincoln, that the first game played on grass at Deepdale after eight years on the plastic.
An entertaining game on a sunny autumn afternoon saw chances at both ends.
In the first half, Preston’s Terry Fleming saw a shot deflected behind while Sale put an effort wide.
Ryan Kidd almost headed into his own net, but North End goalkeeper Barry Richardson got across to save his team-mate’s blushes.
Back at the other end, Stuart Hicks put a header too close to Cottagers keeper Jim Stannard.
Four minutes after the interval, Sale got his first booking from referee Clive Wilkes, for a foul.
Soon after, Sale chased a header from Gareth Ainsworth into the box and appeared to use his hand to knock it past Stannard before shooting into the net.
Mr Wilkes produced a second yellow card and the 6ft 5ins striker headed for an early bath.
North End were forced to withstand a period of pressure as they adapted to having a man less, but soon got themselves on a steady footing and back in the game.
Ian Bryson put a shot over the bar, with Fleming forcing a save from Stannard.
In the 83rd minute, PNE boss John Beck made a double substitution, Trebble and Lee Cartwright coming on for Ainsworth and Fleming.
Fresh legs helped the visitors secure the three points as the clock ticked into time added on.
Cartwright’s run down the right-wing forced a corner, one which Paul Raynor played into the box. It was headed clear and then hooked up field, Andy Fensome chasing back and playing it across to Kidd.
A fine ball from Kidd found Trebble who turned his marker smartly, took a couple of strides into the box before hammering a shot into the roof of the net, in front of the 600 PNE fans.
PNE: Richardson, Fensome, Moyes, Hicks, Kidd, Fleming (Cartwright 83), Bryson, Whalley, Ainsworth (Trebble 83), Sale, Raynor. Sub (not used): Vaughan