The Bees had won the last six meetings between the clubs, Grayson presiding over them all.
It therefore came as relief for the North End manager to see that hoodoo kicked into touch – and in some style too it has to be said – while it was also Grayson’s 100th victory in his time at the Deepdale helm.
That number includes a penalty-shoot win against Oldham in the JPT, victories of that nature sometimes a contentious issue with those who compile statistics.
But in my book they count – after all shoot-out wins have settled the biggest games in the world.
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Grayson reaches his fourth anniversary in charge when the Lilywhites go to Wigan on Saturday, time which can measured in stability, success and progress.
But until this weekend, he had not been able to out-fox Brentford – the first of those six defeats coming in his first month in charge.
The most recent loss had been the most humbling, that 5-0 drubbing at Griffin Park five months ago.
Time has moved on since that horrible afternoon, PNE beaten in just four of their 23 Championship games. A watershed moment in the season you would argue, a turn for the better.
Grayson put his woeful run against Brentford down to ‘the nature of football’, one which pre-dated his arrival at PNE.
“I know there are certain teams who I haven’t got a good record against, or there are certain grounds where I have not done well,” said Grayson.
“On the reverse of that, I have got an absolutely cracking record against some teams. Records are there to be broken, as this one against Brentford showed.
“Somewhere down the line, I will come up against a team I have always done well against and end up losing.
“That is just the nature of football.
“This was probably my first win against Brentford – I think I once got a draw at Griffin Park when I was manager of Leeds.
“But as a rule, they have not been a good team for me to be against.”
Grayson owed much to Aiden McGeady for being the driving force of this victory – one in which they scored four goals for the first time since Wembley.
McGeady scored twice, set up another and pretty much ran the show.
This was Premier League quality in the Championship and gave PNE the edge over a very good and pleasing-on-the- eye Brentford team.
McGeady impressed both on the left wing where he played for more than an hour and then in the No.10 role behind Jordan Hugill. It was a tactical switch from Grayson at 2-1 to move him in-field.
He felt McGeady had been stifled in an attacking sense for a spell when he had to track back and help out Greg Cunningham.
Tom Barkhuizen was put on to do that job on the left – one he did very well – and McGeady dropped into the hole.
He scored Preston’s third goal from that central position and then Daryl Horgan got similar joy in the same area to add a fourth.
It had been McGeady who pulled his side level in the first half after an early Brentford opener, then set up Callum Robinson to make it 2-1.
Quite an afternoon for the ex-Celtic and Spartak Moscow man who trebled his goal tally for the season.
So which role is getting the very best out of McGeady – left, right or off the front?
Talking to him after the game, he said the No.10 role was a relatively new one for him.
McGeady also pointed out that when he plays wide, he is not a touchline-hugging type of winger, preferring to drift inside.
Perhaps the dual role can get the best out of him, start wider and switch in-field as the game stretches – exploit the space that way.
McGeady started this one on the left in a 4-4-2, Horgan recalled to balance things out on the other flank.
It was an absorbing clash on a chilly day, the first and last goals scored by the Bees and sandwiching Preston’s quartet.
The return to scoring was a timely one after they had fired blanks two games running.
PNE fans might have been forgiven for thinking the Brentford jinx was to extend a while longer when Tom FIELD was left unmarked to bullet a header into the roof of the net from a 12th-minute corner.
Never this season had they come back to win a game after conceding the first goal.
North End had different ideas this time, and they were back on level terms within six minutes.
A stray Brentford pass in midfield was intercepted by McGEADY who drove up the pitch and pulled the trigger from 25 yards, his left-foot shot packed with power and finding the bottom corner.
That was the signal for a good spell of pressure from Preston, which in turn gave way to a strong finish to the half by Brentford, which saw two good saves with his legs by Chris Maxwell.
Within seven minutes of the restart, the home side went 2-1 up.
McGeady’s curling cross delivered right-footed from the left found its way through the Bees defence, ROBINSON nipping in to steer it home.
Barkhuizen’s arrival for Robinson in the 69th minute moved McGeady inside and soon they had a third.
Ben Pearson’s header was collected by McGEADY who showed some tricky footwork to get a yard outside the box and curl a right-foot finish into the top corner.
Within two minutes, North End had their fourth goal, HORGAN latching on to a pass from Pearson to run clear and fire left-footed across keeper David Bentley.
Maxime COLIN’S 89th-minute shot from the edge of the box, which struck Paul Huntington and flew past Maxwell, was thankfully only to prove a consolation.
Ton-up then for Grayson, the Brentford hoodoo buried and McGeady showing the class which once made him so sought-after.
Chris Maxwell 8
Made some good saves in the first half, two of them with his feet, as Brentford put North End under pressure. Commanded his box well.
Tyias Browning 8
Strong performance from the Everton loan man on his home debut. Defended well and got forward impressively.
Tom Clarke 7
Limited Lasse Vibe to very few opportunities and got in some timely challenges during the first half.
Paul Huntington 7
Unfortunate to deflect in Maxime Colin’s late goal but otherwise steady enough once PNE got to grips with Brentford’s movement.
Greg Cunningham 7
Made a great goal line clearance with the scoreline at 2-1, colliding with the post in the process. Got up and down the pitch well.
Daryl Horgan 7
Contributed well to the team from the right wing and capped off his performance with his first goal in a Preston shirt
Ben Pearson 8
Claimed assists with North End’s third and fourth goals. Busy in midfield and helped push his side forward in the second half.
Alan Browne 7
Worked hard in midfield, his role to help disrupt the visitors’ movement. Was more about putting his foot in rather than being creative.
Aiden McGeady 9
The game’s outstanding play with two goals and an assist. His two finishes were excellent and Brentford could not cope with him.
Callum Robinson 7
Recalled to the side after two games on the bench, the striker scored PNE’s second goal. Had half-chances in the first half.
Jordan Hugill 8
The focal point of North End’s attack, his hold-up play was excellent. Missed a late chance to give him the goal his play deserved.
Tom Barkhuizen 7
Replaced Robinson in the 69th minute and caught the eye with a powerful running display down the left wing.
Daniel Johnson 6
Came on eight minutes from the end in place of Horgan, to help shore up the midfield and see out the game
Stevie May 6
This late cameo was his first slice of action since November 2015 when he suffered that horrific knee injury. Had a one-on-one.
Subs not used:
Simon Makienok, Jermaine Beckford, Andy Boyle, Anders Lindegaard.
BRENTFORD: Bentley, Colin, Dean, Bjelland, Field, Woods, McEachran (Sawyers 76), Yennaris (Kersschbaumer 76), Jota, Jozefzoon (Canos 56), Vibe. Subs (not used): Egan, Clarke, Barbet, Bonham.
REFEREE: Tony Harrington7
ATTENDANCE: 10,130 (414 away)