David Artell saluted his side’s passion and pride after inflicting a shock defeat on Pompey.
Central defender George Ray’s 77th-minute header settled the Fratton Park clash for a thoroughly-deserved win.
It arrived four days after the Railwaymen had been humbled 4-0 at relegation rivals Hartlepool.
Artell’s men took advantage of the Blues’ lethargy and could well have recorded an even greater scoreline.
It represented a massive boost to the strugglers’ hopes of remaining in League Two during what has been a difficult season.
And Artell was rightly delighted with the commitment demonstrated in Saturday’s fixture.
He told the Crewe Chronicle: ‘It was 11 lads wearing the shirt with honour and pride.
‘We were the better team throughout the game.
‘The fans that came were terrific and we showed how good we can be.
‘It was the best performance, forget Grimsby.
‘The lads were spot on and that’s the way it’s got to be.
‘It was terrific and it should have been more.
‘I can’t remember them (Pompey) having many shots, they had a lot of the ball but didn’t hurt us. We hurt them.
‘It was 11 lads running round and giving everything for the team. We knew were weren’t under pressure.
‘Everyone expected us to lose. They were under pressure. The lads believed it, they bought into it.
‘If they scored early it would have been hard
‘They are a good team but we used the crowd to our advantage.
‘We had three or four really good chances, we’d worked on the counter attacking.
‘The next game is always the biggest one but if we play like we did on Saturday we shouldn’t have any problems.’
Victory put the Railwaymen seven points clear of the bottom two, providing crucial breathing space towards the foot of the table.