PNE’s 2-1 defeat at Cardiff was their first reverse for more than a month, coming on the back of four straight wins and a draw before that.
Both of the Bluebirds’ goals came from the penalty spot, former Myerscough College student Anthony Pilkington on target with them.
Callum Robinson pulled a goal back for the Lilywhites late on but they were unable to find an equaliser.
North End boss Grayson said: “There are not many teams in this division who have won four on the trot and were hoping for a fifth.
“Full credit to the lads for getting to where we are from where we came from – we know where we want to get to.
“It has been a good journey for us over the last few months and we have not suffered disappointment very often.
“We will get the lads ready to go again and face Brighton on Saturday, knowing that we are still in a good position.
“The defeat didn’t drop us down very far and there will be more twists and turns before the season finishes.
“There is no pressure on us, we will keep doing what we have been doing and see where that takes us.
“We cannot get too down about losing to a Cardiff side who are trying to get in the play-offs and have a big budget compared to us.
“As a club, we are enjoying the challenge of trying to compete up there.
“Unfortunately, we couldn’t beat Cardiff but we at least eventually made them work for it towards the end of the game.”
Grayson had no complaint with either of the penalties, even though the second one conceded by Paul Gallagher bordered on the soft side.
A decision at the other end also saw Adam Reach have an effort chalked off after he had turned home Robinson’s cross, the flag going up against Joe Garner for offside.
Said Grayson: “I think Garner was given offside – he made a movement towards the ball which in this day and age is offside.
“I thought both were penalties, Gally got a little tug on their lad for the second.
“If it had been the other way round, we would have been looking for it.
“Their second penalty came at a time when we had got ourselves on top.
“We responded well with a good goal from Callum and I thought we might get another because they were hanging on a bit towards the end.
“To be fair, Cardiff managed the game well, they had an experienced manager who was making substitutions to slow our momentum.
“Maybe in those last few minutes, we didn’t put enough balls into the box – we should have tried to go a bit uglier to test them that way.”
Goalscorer Robinson had missed training on Thursday and Friday because of illness.
He travelled separately to Wales to avoid spreading the virus to his team-mates.